IRLF 


SB    SbD 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 


PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 
MRS.  PRUDENCE  W.  KOFOID 


SPECULATIONS. 


SOLAR  HEAT,  GRAVITATION, 


AND 


SUJST  SPOTS. 


By  J.  H.  KEDZIE. 


Whence  are  thy  beams,  O,  Sun!  thy  everlasting  light?— Oss IAN. 

Some  are  much  surprised  that  I  should,  as  they  think,  venture  to  oppose 
the  conclusions  of  Newton;  but  here  there  is  a  mistake.  I  do  not  oppose 
Newton  on  any  point;  it  is  rather  those  who  sustain  the  idea  of  action  at  a 
distance  that  contradict  him. —  DR.  FARADAY. 

The  very  source  and  font  of  day 
Is  dashed  with  wandering  isles  of  night.— BELGRAVIA. 


CHICAGO: 
S.    C.    GR1GGS    AND    COMPANY. 

1886. 


COPYRIGHT,  1886, 
BY  S.  C.  GRIGGS  AND  COMPANY. 


K37 


PREFACE. 

THE  author's  task  is  done,  and  it  only  remains  for 
him  to  apologize  to  the  public  for  inflicting  one 
more  book  on  a  book-ridden  world. 

The  public,  however,  cannot  complain  of  a  surfeit 
of  literature  on  the  subject  I  have  chosen.  Probably 
not  one  work  has  been  written  on  the  Sun  —  to  us  the 
grandest  and  most  beneficent  object  in  nature  -  to  one 
million  of  fiction. 

As  will  be  seen  from  the  title,  the  themes  here 
treated  are  three  apparently  disconnected  subjects,  but 
if  I  am  correct,  they  form  a  closely  connected  trinity, 
depending  upon  a  common  principle. 

The  positions  advanced  in  this  work  may  seem  bold 
and,  at  first  glance,  revolutionary.  But  a  closer  view, 
I  trust,  will  convince  the  reader  that  not  a  single  well 
settled  principle  of  science  has  been  assailed.  Thus : 
On  the  subject  of  solar  heat  there  are  not  less  than  five 
or  six  different  theories  advanced  by  eminent  scientists. 
A  new  theory  cannot,  therefore,  be  considered  as  con- 
flicting with  any  settled  doctrine  on  this  subject. 

In  regard  to  gravitation,  the  field  is  still  more  com- 
pletely unpreoccupied.  There  is  no  settled  doctrine  as 
to  the  cause  of  gravitation,  and  not  even  a  plausible 


IV  PREFACE. 

theory  that  I  am  aware  of.  It  is  equally  true  that  there 
is  no  settled  doctrine  among  scientists  in  regard  to  the 
cause  of  sun  spots.  A  number  of  ingenious  theories 
have  been  advanced,  but  none  have  met  with  general 
acceptance,  and  there  is  not  one  which  even  professes 
to  account  for  all  the  phases  of  those  wonderful  phe- 
nomena. 

The  writer  thought  at  one  time  that  he  would  be 
obliged  to  dissent  from  a  generally  accepted  doctrine  in 
regard  to  "  potential  energy  "  ;  but  subsequent  reading 
showed  him  that  he  had  been  anticipated,  in  the  views 
advanced  by  at  least  two  scholars  of  eminence  —  Judge 
J.  B.  Stallo  and  S.  Tolver  Preston. 

The  writer,  therefore,  though  a  debtor  to  all  scholars, 
from  the  times  of  Copernicus  to  the  present,  has  im- 
pugned the  accepted  work  of  none.  On  the  contrary, 
he  has  addressed  himself  wholly  to  unsolved  problems 
in  science.  Since  astronomers  have  swept  the  vault  of 
heaven  with  their  magic  tubes,  and  calculated  the  paths 
of  planets  and  satellites  by  the  laws  of  projection  and 
gravitation,  it  cannot  be  considered  presumptuous  to 
inquire  reverently  into  the  source  of  gravitation  itself ; 
and  if  in  so  doing  the  suspicion  arises,  and  will  not 
down,  that  gravitation  is  connected  on  one  hand  with 
solar  heat,  and  on  the  other  with  sun  spots,  by  a  single 
well  known  principle,  what  is  the  writer  to  do  but  to 
announce  his  suspicion,  and  give  his  reasons  therefor  2 

Though  the  writer  has   chosen  to  apply  the  term 


PREFACE.  V 

"speculations"  to  the  views  herein  advanced  until  in- 
dorsed by  higher  authority,  still  he  must  confess  that 
not  without  some  misgivings  he  has  finally  become  a 
convert  to  his  own  opinions.  He  has,  therefore,  no 
apology  to  offer  for  advocating  what  he  believes  to  be 
true  with  all  the  earnestness  and  zeal  which  truth  de- 
mands of  her  votaries. 

For  all  the  facts  and  principles  of  value  in  the  fol- 
lowing pages,  though  not  always  for  the  use  made  of 
them,  the  writer  is  indebted,  as  all  the  world  is,  first  to 
Sir  Isaac  Newton ;  and  scarcely  less  to  the  great  minds 
of  the  present  day.  Though  illustrious  all,  they  are  too 
numerous  to  be  mentioned  by  name.  I  desire  to  ac- 
knowledge my  indebtedness  to  all  as  fully  as  if  I  could 
thank  each  one  in  person. 

These  chapters  are  most  deferentially  submitted  by 
the  author  to  the  candid  judgment  of  the  learned  public. 
He  cannot  expect,  and  would  not  desire,  the  acceptance 
of  the  views  here  presented  until  it  is  found  on  the  full- 
est examination,  that  they  conform  to  all  the  conditions 
of  truth,  and  conflict  with  no  settled  fact  or  principle  of 

science. 

J.  H.  KEDZIE. 

EVANSTON,  ILL.,  MAY,  1886. 


CONTENTS. 


PART  I. 
CHAPTER  I. 

PA&K. 

THE  SUN  —  POSTULATES, 1 

CHAPTER  II. 

THEORIES  IN  REGARD  TO  THE  LIGHT  AND  HEAT  OF 
THE  SUN  —  CONFLAGRATION  THEORY  —  METE- 
ORIC THEORY  —  CONDENSATION  THEORY,  .  .  4 

CHAPTER  III. 

POTENTIAL  ENERGY  —  ATMOSPHERIC  CONDENSA- 
TION,   17 

CHAPTER  IV. 

DR.  SIEMEN'S  NEW  THEORY  OF  THE  SUN  —  CON- 
VECTION CURRENTS  —  ENORMOUS  QUANTITY  OF 
HEAT  EMITTED  BY  THE  SUN  —  QUOTATIONS,  .  24 

CHAPTER  V. 

A  NEW  THEORY  OF  SOLAR  HEAT  —  DIFFUSION  - 
EQUALIZATION  —  CONSERVATION  — TRANSFORMA- 
TION,      •  36 

vii 


VU1  CONTENTS. 

CHAPTER  VI. 

PAOE. 

WHAT  is  THE  TRUE  SOURCE  OF  SOLAR  HEAT?  — 

ILLUSTRATIONS  AND  ARGUMENTS,       ....       44 

CHAPTER  VII. 

SOLAR    HEAT   CONTINUED  —  FURTHER    ILLUSTRA- 
TIONS AND  ARGUMENTS,     .......        51 

CHAPTER  VIII. 
WHY  HAS  THE  EARTH  COOLED  OFF  AND  NOT  THE 


59 


CHAPTER  IX. 
NEBULAR  HYPOTHESIS,     ........       68 

CHAPTER  X. 

WHAT  is  ENERGY  ?  —  POTENTIAL  ENERGY,        .      .        80 

CHAPTER  XI. 

DISSIPATION  OF  ENERGY,  93 


PART  II. 

CHAPTER  I. 
GRAVITATION  ;  ITS  NATURE  AND  CAUSE,      ...        99 

CHAPTER  II. 

ILLUSTRATIONS    OF    GRAVITATION  —  AUTHORITIES 
QUOTED, 106 


CONTENTS.  IX 

CHAPTEK  III. 

PAGE. 

GRAVITATION  NOT  A  POSITIVE  FORCE  EXERTED  BY 

THE  SUN, 114 

CHAPTER  IV. 

SUMMARY  OF  PREVIOUS  ARGUMENTS  —  ASTRONOM- 
ICAL ARGUMENT, 117 

CHAPTER  V. 

GRAVITATION   CONSIDERED   IN  RELATION   TO   THE 

CORRELATION  AND  CONSERVATION  OF  ENERGY,  .      126 

CHAPTER  VI. 

ACTION  AT  A  DISTANCE  —  PROPULSION  vs.  TRAC- 
TION,   .  ....  .  .  131 

CHAPTER  VII. 

'  GRAVITATION  COMPARED  WITH  LIGHT  AND  HEAT,     138 

CHAPTER  VIII. 

ILLUSTRATIONS   OF  GRAVITATION   AND  WEIGHT  — 

SEMI-DELUSIONS, -.  144 

CHAPTER  IX. 
LE  SAGE'S  ULTRAMUNDANE  CORPUSCLES,      .      .      .     152 

CHAPTER  X. 

OMNIPOTENT  ATOMS  —  ASTRONOMICAL  AND  OTHER 
OBJECTIONS  TO  THE  AVAILABILITY  OF  ETHER  ix 
PRODUCING  GRAVITATION,  .  .  .  .  .  .  155 


CONTENTS. 

CHAPTER  XL 


ONTOLOGY 


CHAPTER  XII. 
STRESS  —  STRAIN  —  TENSION,     ......      167 

CHAPTER  XIII. 
THE  CAVENDISH  EXPERIMENT,    ......      171 

CHAPTER  XIY. 

ILLUSTRATION  FROM  EXPERIMENTS  IN  DIFFERENTIAL 
GRAVITATION  BY  DRS.  KONIG  AND  RICHARZ,  .  176 

CHAPTER   XV. 
REDUCTIONES  AD  ABSURDA,   .......      182 

CHAPTER  XVI. 

CIRCUMSTANCES  UNDER  WHICH  HEAT  CHANGES  TO 
MECHANICAL  FORCE  AND  OTHER  FORMS  OF  EN- 
ERGY, AND  VICE-  VERSA  —  METAMORPHOSIS  OF 
MOTION,  ....  ........  185 

CHAPTER  XVII. 
WHAT  is  THE  ETHER  ?      ........     196 

CHAPTER  XVIII. 
ETHEREAL  VIBRATIONS  .........     206 

CHAPTER  XIX. 

CONCLUDING  REMARKS  ON  GRAVITATION,     .      .      .     213 


CONTENTS.  XI 

PART  III. 
CHAPTER  I. 

PAG». 

DESCRIPTION  AND  P!ISTORY  OF  SUN  SPOTS,       .      .     219 

CHAPTER  IT. 

A  NEW  THEORY   OF   SUN    SPOTS  —  THE  PHOTO- 
SPHERE THE  HOTTEST  PART  OF  THE  SUN,      .      .     224 

CHAPTER  III. 

THE  SUN'S  HEAT  DERIVED  FROM  THE  ETHER,  AND 

NOT  FROM  His  INTERIOR  —  CAUSE  OF  SUN  SPOTS,     229 

CHAPTER  IV. 

ARGUMENT  FROM  THE  UNEQUAL  ROTATION  OF  THE 
SUN  SPOTS 234 

CHAPTER  Y. 

DISTRIBUTION  OF  SUN  SPOTS, 240 

CHAPTER  VI. 

PERIODICITY  OF  SUN  SPOTS, 248 

CHAPTER  VII. 

THE  PHOTOSPHERE  PROBABLY  COMPOSED  OF  INCAN- 
DESCENT CARBON  VAPOR, 256 

CHAPTER  VIII. 
APPEARANCE  OF  SUN  SPOTS,       ......     265 


Xll  CONTENTS. 

CHAPTER  IX. 

PAGE. 

RECAPITULATION, 27$ 

CHAPTER  X. 

UNITY  OF  THE  PROPOSITIONS  CONCERNING   SOLAR 

HEAT,  GRAVITATION,  AND  SUN  SPOTS.     .      .      .      284 

CHAPTER  XI. 
IF- 287 

CHAPTER    XII. 
CONCLUSION, 290 


SOLAR  HEAT,  GRAVITATION,  AND  SUN  SPOTS. 


PART  I.- SOL  AH  HEAT. 


CHAPTEK  L 

THE    SUN —  POSTULATES. 

0  thou  that  rollest  above,  round  as  the  shield  of  my  fathers! 
Whence  are  thy  beams,  0  Sun!  thy  everlasting  light?  Thou 
comest  forth  in  thy  awful  beauty;  the  stars  hide  themselves  in 
the  sky ;  the  moon,  cold  and  pale,  sinks  in  the  western  wave,  but 
thou  thyself  movest  alone.  Who  can  be  a  companion  of  thy 
course  V 

The  oaks  of  the  mountains  fall ;  the  mountains  themselves 
decay  with  years;  the  ocean  shrinks  and  grows  again;  the  moon 
herself  is  lost  in  heaven,  but  thou  art  forever  the  same,  rejoicing 
in  the  brightness  of  thy  course.  When  the  world  is  dark  with 
tempests,  when  thunder  rolls  arid  lightning  flies,  thou  lookest  in 
thy  beauty  from  the  clouds,  and  laughest  at  the  storm. —  OSSIAN. 

""TYTHENCE  are  thy  beams,  O  Sun!  thy  ever- 
VV  lasting  light?"  is  a  question  that  has  been 
asked  by  every  thoughtful  mind  in  every  age.  With 
the  advent  of  what  is  called  the  "New  Astronomy  "- 
that  is,  an  astronomy  that  is  not  satisfied  with  a 
knowledge  of  the  laws  and  motions  of  the  heavenly 
bodies,  but  seeks  to  penetrate  the  causes  of  celestial 
phenomena  —  this  question  has  excited  a  new  and 
increasing  interest.  Until  science  solves  for  us  this 

i 


2  SOLAR    HEAT. 

problem,  the  field  (and  a  very  broad  one  it  is)  is  free 
and  open  for  speculation,  even  the  most  daring. 

In  so  boundless  a  field  as  the  universe,  where  the  un- 
known bears  so  large  a  proportion  to  the  known,  and 
the  disproof  of  theories,  however  grotesque  and  extrav- 
agant, is  difficult,  the  temptation  to  allow  the  imagina- 
tion to  run  riot  is  great.  Its  value  in  physical  investi- 
gations cannot  be  overestimated,  yet  it  should  never  be 
the  blind  flounderings  of  an  untaught  and  untamed 
imagination,  but  rather  the  advanced  thought  of  clear 
minds,  guided  by  known  principles,  outrunning  for 
the  time  the  slower  processes  of  demonstration,  but 
always  returning  to  verify  preconceived  theories  by 
sound  reasoning  or  actual  experiment. 

Such  has  been  my  desire  and  aim.  If  I  have  not  al- 
ways brought  the  best  arguments  to  sustain  my  theories 
I  have  at  least  produced  the  best  my  slender  repertoire 
could  supply.  If  I  have  in  any  instance  touched  the 
key  note  to  future  discoveries,  the  spirit  of  keen  research 
characteristic  of  modern  science  will  speedily  furnish 
the  experimental  and  mathematical  proofs. 

POSTULATES. 

In  the  commencement  of  this  discussion  it  is  neces- 
sary to  lay  down  two  or  three  propositions  which, 
though  not  strictly  self-evident,  have  acquired  the 
weight  and  authority  of  axioms  with  the  scientific 
world.  The  first  is  the  virtually  infinite  duration  in 
some  form  of  the  universe  in  the  past.  Not  that  scien- 
tific men  would  deny  the  fact  of  creation,  but  locate  it  so 
far  back  in  the  dim  by-gone  ages  that  to  our  feeble  con- 
ceptions its  date  is  in  eternity  rather  than  in  time.  It 
would  be  difficult  to  conceive  of  a  date  when  the  bright 


POSTULATES.  8 

blue  heavens  were  black  and  starless,  and  space  from 
end  to  end  and  from  bottom  to  top  was  without  an  in- 
habitant, except  a  quiescent  Deity,  dwelling  alone  in 
darkness  and  silence,  for  Creator,  antecedently  to  crea- 
tion, we  could  not  call  Him. 

Another  postulate  is  the  virtually  infinite  extension 
of  the  universe  in  space;  that  is,  that  space  is  peopled 
with  suns  and  worlds,  comets  and  nebulae,  without  limit 
or  bound.  If  not,  let  us  try  to  conceive  of  an  imagi- 
nary circle  drawn  with  a  radius  sufficient  to  inscribe  the 
remotest  sun  or  world  in  the  universe.  Then  rotate 
this  circle  on  one  of  its  diameters  as  an  axis,  and  by  the 
supposition  we  have  the  universe  in  an  imaginary  shell. 
Again,  we  ask  the  question,  what  lies  outside  of  this 
hollow  sphere?  By  the  supposition  the  answer  should 
be  —  blank  nothingness,  empty  space,  from  which  the 
last  waves  of  light  and  heat  have  died  out  in  darkness 
and  death.  But  is  the  human  mind  satisfied  with  such 
an  answer?  If  not,  then  the  only  answer  possible  is — 
suns  and  systems,  suns  and  systems,  ad  infinitum. 

A  third  postulate  which  will  be  most  readily  con- 
ceded, for  none  has  been  received  with  more  universal 
acceptance,  is  the  "conservation  of  energy" — that  is, 
that  energy  of  every  kind,  whether  in  the  form  of  heat, 
mechanical  motion,  electricity,  magnetism,  chemical 
action  or,  I  will  add,  gravitation,  cannot  be  lost,  wasted, 
or  annihilated  any  more  than  matter  can  be ;  but  on  the 
contrary,  continues  not  only  to  exist  but  to  act  forever 
either  in  the  same  or  in  some  other  form,  into  which  it 
is  capable  of  being  converted. 

These  postulates  I  shall  take  the  liberty  of  using  as 
often  as  I  shall  have  occasion  hereafter. 


CHAPTER   II. 

THEORIES  IN  REGARD   TO   THE   LIGHT  AND    HEAT   OF 

THE  SUN -CONFLAGRATION  THEORY  — METEORIC" 

THEORY  — CONDENSATION  THEORY. 

The  God  sits  high  exalted  on  a  throne 

Of  blazing  gems,  with  purple  garments  on; 

The  hours,  in  order  ranged  on  either  hand, 

And  days,  and  months,  and  years,  and  ages  stand. 

Here  spring  appears  with  flowery  chaplets  bound; 

Here  summer  in  her  wheaten  garland  crowned; 

Here  autumn  the  rich  grapes  besmear; 

And  hoary  winter  shivers  in  the  rear.  — OVID. 

BEFORE  venturing  upon  perhaps  the  boldest  specu- 
lation yet  advanced  in  regard  to  the  source  of  the 
light  and  heat  of  the  sun,  I  wish  to  advert  briefly  and 
most  deferentially  to  some  of  the  theories  advanced  by 
distinguished  scientists  on  this  subject.  If  all  of  these 
should  appear  untenable  it  will  not  prove  my  theory 
correct.  But  it  will  at  least  show  the  necessity  for 
assigning  a  more  satisfactory  cause,  for  cause  there  cer- 
tainly must  be,  for  the  light  and  heat  which  the  sun 
gives  off  from  age  to  age. 

THE   CONFLAGRATION   THEORY. 

The  first  theory  I  shall  notice  is  that  the  sun  is  a 
vast  magazine  of  combustible  matter,  which  by  fierce 
Conflagration  not  only  supplies  the  light  and  heat  fur- 
nished to  the  earth  and  the  other  planets  of  our  system, 
but  two  hundred  and  thirty  million  times  as  much 
more,  which  is  radiated  into  space  and  supposed  to  be 

4 


THE    METEORIC    THEORY.  5 

lost,  One  answer  to  this  theory  is  this :  If  the  universe 
has  existed  through  a  past  eternity,  the  sun,  no  matter 
what  his  size  or  material,  would  have  been  burnt  out  or 
oxidized  millions  of  ages  ago.  Another  answer  is,  that 
combustion,  at  the  surface  of  the  sun,  is  impossible.  It 
is  not  necessary  here  to  go  into  an  explanation  of  the 
chemical  changes  in  combustion  or  the  circumstances 
under  which  it  occurs.  It  is  sufficient  to  state  that  the 
demonstrated  temperature  of  the  photosphere  of  the  sun 
is  such  that  in  it  all  chemical  compounds  would  in- 
stantly be  decomposed  and  their  elements  dissociated, 
and  that  combustion  could  only  take  place  at  a  much 
lower  temperature  than  that  which  prevails  at  the  sur- 
face of  the  sun.  Not  only  this,  but  millions  of  tons 
of  coal  added  to  the  sun,  if  that  were  possible,  would 
undergo  rarefaction  instead  of  condensation,  and  so 
would  produce  cold  instead  of  heat.  But  it  is  neither 
necessary  nor  magnanimous  to  assail  a  theory  that  no 
longer  has  any  friends. 

THE  METEORIC   THEORY. 

Another  theory  assumes  that  vast  numbers  of  me- 
teorites are  constantly  falling  into  the  sun,  and  that  he 
is  warmed  by  the  heat  given  out  by  their  arrested  mo- 
tion.* To  this  there  are  several  objections. 

1.  It  is  unproved. 

2.  The  theory  indicates  only  a  temporary  provision. 
The  meteors  would  all  be  absorbed  in  time  by  our  sun 
and  other  suns,  and  the  solar  fires  would  ultimately  die 
out  for  want  of  fuel. 

3.  If  true,  the  sun  would  be  constantly  augmenting 
in  mass  by  the  added  matter.     Its  power  of  attraction 

*See  "Other  Worlds  than  Ours,"  by  R.  A.  Proctor,  pages  215-217. 


0  SOLAR    HEAT. 

would  be  steadily  increasing.  The  orbits  of  the 
planets  would  be  continually  narrowing  in  the  form 
of  a  spiral,  and  it  would  be  only  a  question  of  time 
when  the  sun  would  absorb  our  earth  and  all  the  mem- 
bers of  our  system. 

4.  If  this  process  had  been  in  operation  through  a 
past   eternity   the   result   would    probably   have    been 
reached  millions  of  years  ago. 

•  '  o 

5.  Newtonian  laws  require,  and  observation  proves, 
that  all  the  members  of  our  system  revolve  around  the 
sun  in  well  defined  orbits ;  and  it  would  be  as  impossi- 
ble for  the  smallest  of  them  to  bolt  from  its  orbit  and 
fall  into  the  sun  as  for  the  earth  to  do  the  same  thing. 
Collisions  between  the  earth  and  small  bodies  moving  in 
the  same  plane  and  about  the  same  distance  from  the 
sun  are  both  possible  and  common,  and  the  earth  would 
be  much  more  likely  than  the  sun  to  be  set  on  lire  from 
this  cause.     These  small  bodies  collide  with  the  earth 
or  its  atmosphere  while  moving  in  their  own  orbits,  but 
in  order  to  collide  with  the  sun  they  would  have  to  leave 
their  orbits,  which  is  an  impossibility. 

6.  One  of   the   strongest    arguments   to   my  mind 
against  the  meteoric  theory  is,  that  it  involves  the  truth 
of   the   wholly   unproved   assumption   that   the   space 
through  which  the  sun,  with  his  attendant  worlds,  is 
moving,  is  filled  with  wandering  meteors.    As  there  are 
innumerable  other  suns,  analogy  would  require  that  they 
all  be  warmed  in  the  same  manner,  so  that  universal 
space  must  be  pervaded  by  this  meteoric  matter.    If  so, 
the  meteors  must  be  utterly  unlike  the  minute  bodies 
which  are  unable  to  penetrate  even  our  thin  atmos- 
pheric envelope,  and  rarely  reach  the  ground.    They  must 
necessarily  be  bodies  more  nearly  resembling  our  moon 


THK    MKTKOK1C    THEORY. 


or  the  inferior  planets  in  size.  If  all  space  is  traversed 
by  such  bodies  falling  like  hail  on  the  sun  by  virtue  of 
his  motion  through  space,  they  should  fall  as  thick  and 
fast  upon  the  earth  in  proportion  to  its  surface  as  upon 
the  sun. 

The  earth  would  not  only  become  as  hot  as  the  sun, 
but  would  be  in  great  danger  of  being  dislodged  from 
her  orbit  by  such  collisions. 

If  it  be  suggested  that  the  sun's  superior  attraction 
would  concentrate  upon  himself  a  much  larger  percent- 
age of  these  meteors  than  would  fall  upon  the  earth,  I 
reply :  If  these  meteors  are  within  the  sphere  of  the 
sun's  attraction,  then  they  are  members  of  his  family, 
and  would  revolve,  like  all  the  other  members,  in  closed 
orbits  under  the  influence  of  tangential  as  well  as  cen- 
tripetal forces,  and  therefore  could  not  fall  upon  the  sun. 

1.  The  effect  of  a  collision  between  a  meteor  and  the 
sun,  if  such  could  occur,  which  I  have  endeavored  to 
show  is  highly  improbable,  if  not  impossible,  can  readily 
be  understood  by  comparison  with  collisions  upon  the 
earth.  In  fact,  all  we  know  about  hypothetical  collisions 
in  the  sun  is  inferred  from  what  we  have  learned  in 
regard  to  mundane  collisions. 

(1)  Let  two  elastic  bodies,  as  billiard  balls,  moving 
with  equal  velocity  in  opposite  directions,  collide;   an 
exchange  of  motion  will  take  place,  action  and  re-action 
will  be  equal.     Very  little  heat  will  be  developed,  but 
the  balls  will  each  return  by  the  same  path  and  with 
nearly  the  -same  velocities  as  those  by  which  they  ap- 
proached each  other. 

(2)  If  the  bodies  were  inelastic  leaden  balls,  nearly 
the  whole  of  their  molar  motion  would  turn  to  vibratory 


8  SOLAR    HEAT. 

motion  or  heat,  and  they  would  remain  where  their  mo- 
tion was  arrested,  without  recoil. 

(3)  If  one  ball  were  lead  and  the  other  ivory,  each 
would  behave  as  before  stated. 

Applying  these  principles  to  the  hypothetical  mete- 
ors falling  into  the  sun.  A  cold  meteor  or  little  planet 
would  probably  be  inelastic,  while  the  sun's  atmosphere, 
and  probably  his  whole  mass,  with  the  possible  excep- 
tion of  his  central  core,  is  gaseous  and  highly  elastic. 
The  arrested  motion  of  the  inelastic  meteor  would  turn 
to  heat,  but  the  motion  communicated  to  the  elastic 
matter  of  the  sun  would  undergo  no  change  in  kind, 
and  would  result  only  in  an  infinitesimal  change  of  the 
sun's  path. 

If  the  heat  developed  by  the  arrested  motion  of  the 
inelastic  meteor  should  be  just  sufficient  to  raise  its 
whole  mass  to  a  temperature  equal  to  that  of  the  sun, 
the  temperature  of  the  sun  would  neither  be  increased 
nor  diminished.  Only  in  the  improbable  event  of  the 
meteor's  developing  more  heat  than  would  be  necessary 
to  raise  its  own  mass  to  an  equality  with  the  sun,  could 
it  increase  the  sun's  temperature. 

The  fact  that  the  whole  mass  of  the  colliding  meteor 
must  first  be  raised  to  an  equality  with  the  sun  before 
it  will  have  any  surplus  heat  to  impart  to  the  latter, 
seems  to  have  been  entirely  overlooked  by  nearly  all 
writers  on  the  subject. 

But  this  is  not  all.  If  S.  Tolver  Preston  is  good 
authority,  which  few  will  question,  all  the  heat  devel- 
oped by  the  falling  of  a  meteor  upon  the  sun  is  recon- 
verted into  translatory  motion.  This  author,  in  his 
"  Physics  of  the  Ether,"  page  124,  says :  "In  the  case  of 
matter  coining  together  at  a  high  speed  under  the  long 


THE    METEORIC    THEORY.  9 

continued  action  of  gravity,  transiatory  motion  is  con- 
verted into  vibratory  motion  (heat)  and  then  re-converted 
into  translatory  motion,"  and  therefore  no  actual  addi- 
tion to  the  sun's  heat  could  arise  'from  collisions  with 
meteors. 

8.  An  argument  opposed  to  the  meteoric  theory 
above  hinted  at,  but  deserving  fuller  mention,  is  that 
it  seems  to  be  a  universal  law  of  nature  that  all'  plan- 
etary bodies,  and  even  planetoids,  are  subject  to  both 
centrifugal  and  centripetal  forces.  We  have  seen  that 
these  hypothetical  meteoric  bodies  do  not  belong  to  our 
system.  If  they  did,  their  centrifugal  and  centripetal 
forces  would  be  balanced,  and  they  could  not  fall  into 
the  sun.  If  they  belong  to  some  other  system  and  re- 
volve around  some  other  sun,  we  ask:  What  sun? 
Everyone  with  the  slightest  knowledge  of  physical  laws 
knows  that  the  force  of  gravitation  exerted  by  any 
single  fixed  star  is  absolutely  infinitesimal  within  the 
limits  of  our  system.  Therefore,  no  such  bodies,  either 
domestic  or  foreign,  can  exist,  either  at  rest  or  in  mo- 
tion, within  our  system. 

Our  sun  is  now,  always  has  been,  and  no  doubt 
always  will  be,  sufficiently  distant  from  all  other  suns 
to  prevent  the  possibility  of  his  clashing  with  other 
systems. 

No  person  who  has  a  correct  idea  of  the  machinery 
of  the  heavens,  will,  I  think,  for  a  moment  believe  in  the 
existence  of  celestial  bodies  floating  idly  in  space.  ~It 
would  simply  be  time  wasted  to  point  out  the  many 
absurdities  it  would  involve. 

Newton  demonstrated  that  every  planet  in  our  sys- 
tem must  necessarily  move  in  some  one  of  the  curves 
known  as  conic  sections.  The  same  is  equally  true  of 


10  SOLAK    HEAT. 

other  systems,  if  such  there  are,  as  all  believe.  There- 
fore, wo  conclude  there  are  no  wandering  lawless  bodies 
in  the  heavens;  and  certainly  not  in  such  crowds  as  to 
keep  the  sun  under  perpetual  bombardment.* 

9.  The  following  argument  would  not  alone  be  con- 
clusive, but  it  harmonizes  with  all  the  others.  All  men 
believe  in  the  stability  of  the  order  of  nature.  .Men 
have  called  in  question  the  existence  of  God,  of  immor- 
tality, of  the  soul,  but  none  have  questioned  the  stabil- 
ity and  permanency,  at  least  in  our  day,  of  the  order  of 
nature.  We  believe  the  sun  will  rise  to-morrow  as  cer- 
tainly as  —  as  what;!  Why,  as  certainly  as  that  the  sun 
will  rise  to-morrow.  We  can  think  of  nothing  more 
absolutely  certain.  We  believe  just  as  firmly  that  the 
sun  would  rise  to  very  little  purpose  if  he  did  not  shine 
with  his  accustomed  fervor.  We  could  hardly  say 
"how  firm  a  foundation"  we  have  for  this  universal 
belief,  if  it  depended  wholly  on  the  sun's  meeting  by 
chance  every  day  just  the  right  number  of  wandering 
meteors  of  just  the  proper  mass  and  proper  velocity  to 
produce  exactly  the  same  amount  of  heat  by  arrested 
motion.  It  would  seem  by  far  too  precarious  and  un- 
certain a  ground  for  the  firm  faith  we  repose  in  nature. 

CONDENSATION  OR  SHRINKAGE. 

Another  source  to  which  the  light  and  heat  of  the 
sun  is  ascribed,  is  the  condensation  or  shrinkage  of  the 
solar  mass,  or  by  flagellating  himself  by  the  descent 
upon  himself  of  parts  of  himself.  The  contraction  of 
the  sun,  if  such  be  the  fact,  which  is  only  assumed  and 

*  All  the  known  asteroids  aggregate  less  than  ^-^^  of  either  the  volume  or 
mass  of  the  earth,  and  none  of  them  are  falling  into  the  sun.  See  Winchell's 
"World  Life,11  page  175. 


CONDENSATION    OR    SHHTNKAOE.  11 

not  proved,  can  only  arise  from  his  first  cooling  down  by 
the  loss  of  a  portion  of  his  heat,  and  each  successive 
contraction  is  preceded  and  caused  by  a  preceding  loss 
of  heat. 

This  theory,  favored  by  Ilelmholtz,  Young,  and 
many  others,  is  ingenious  and  plausible,  but  has,  in 
common  with  nearly  all  others,  the  defect  of  making 
our  sun,  and  by  analogy  all  suns,  to  be  machines  once 
wound  up,  but  now  running  down  hopelessly  and  help- 
lessly by  enormous  emanations  given  out  but  never 
returned  —  an  appalling,  irreparable  waste. 

The  great  majority  of  judicious  scientists,  however, 
for  want  of  a  better,  still  adhere  to  the  theory  that  the 
sun's  heat  is  produced  by  his  contraction  upon  himself. 
This  is  not  based  upon  any  observed  diminution  of  the 
sun's  diameter,  for  not  the  slightest  decrease  has  been 
observed  since  man  became  an  astronomical  animal, 
although  the  sun  has  given  off  during  that  time  an 
amount  of  heat  for  which  figures  can  hardly  furnish  an 
adequate  expression.  Neither  is  this  theory  based  upon 
experiment.  Let  us  try  one  on  paper,  where  we  will 
be  in  no  danger  of  burning  our  fingers.  Take  a  cannon 
ball  cast  with  an  eye,  to  which  a  chain  can  be  attached; 
raise  it  to  a  white  heat  in  a  furnace,  and  then  hang  it  to 
the  limb  of  an  apple  tree  of  a  winter's  night ;  or  if  you 
prefer,  suspend  it  in  the  exhausted  receiver  of  an  air- 
pump.  Will  it  maintain  its  temperature  in  either  case 
by  contraction  while  cooling?  We  know  well  enough 
that  it  would  be  stone  cold  in  the  morning.  I  can  see 
no  unfairness  in  the  comparison,  ridiculous  as  it  may 
seem.  It  matters  not  whether  the  cooling  is  effected  by 
conduction  of  the  air  or  by  radiation.  It  is  the  cooling, 
however  effected,  that  is  supposed  to  cause  the  sun's 


12  SOLAR    HEAT. 

contraction,  and  by  contraction  the  development  of 
solar  heat.  If  the  open  air  is  objected  to,  we  will  allow 
the  ball  to  cool  by  radiation  in  vacuo.  According  to 
the  contraction  theory  of  heat,  the  ball  should  remain 
for  thousands  of  years  at  least,  without  perceptible  di- 
minution of  his  heat.  The  law  should  be  the  same  for 
all  bodies,  large  or  small.  There  is  no  claim  by  its  ad- 
vocates that  the  law  applies  only  to  bodies  of  a  particu- 
lar size.  According  to  this  theory,  a  large  body  by 
contraction  would  generate  sufficient  heat  to  maintain 
the  temperature  of  a  large  body ;  a  small  body,  sufficient 
to  maintain  the  temperature  of  a  small  body.  Neither 
does  it  seem  to  be  a  valid  objection  to  the  comparison 
that  the  contraction,  in  the  case  of  the  cannon  ball,  is 
caused  mainly  by  cohesive  attraction.  Both  the  sun 
and  the  ball  are  subject  alike  to  the  action  of  both  grav- 
itative  and  cohesive  attraction,  and  though  compression 
by  gravitation  in  the  case  of  the  ball  is  infinitesimal,  it 
is  not  more  so  in  comparison  with  that  of  the  sun,  than 
is  the  mass  of  the  ball  in  comparison  with  that  of  the 
sun. 

But  the  sun  has  been  hung  up  in  the  heavens  for 
thousands  of  years  within  the  historic  period  of  our 
race,  and  perhaps  for  millions  of  ages.  For  five  thous- 
and years  his  light  and  heat  have  undergone  no  percep- 
tible diminution.  If  my  comparison  is  fair,  this  light 
and  heat  could  no  more  be  produced  by  contraction 
from  cooling  than  a  white-hot  cannon  ball  can  be  kept 
at  white  heat  indefinitely  by  allowing  it  to  contract  by 
cooling. 

The  only  reply  I  apprehend  that  can  be  made  to 
this  comparison  is  —  that  a  ball  has  a  much  larger  sur- 
face in  proportion  to  its  mass  than  the  sun,  and  would 


CONDENSATION    OR    SHRINKAGE.  13 

therefore  radiate  its  heat  much  more  rapidly.  Admit 
it  —  what  then?  Acccording  to  this  theory,  the  faster 
a  body  radiates  away  its  heat,  the  more  rapidly  it 
shrinks  and  the  greater  the  amount  of  heat  that  should 
be  developed.  The  white-hot  ball  by  this  rapid  cooling 
and  resulting  contraction  should,  on  this  theory,  have 
its  temperature  increased  rather  than  diminished. 

The  contraction  of  the  sun,  if  it  exists,  is  the  result 
of  the  absolute  loss  to  the  sun,  or  transference  to  other 
regions,  of  the  immense  quantities  of  heat  given  out  by 
his  radiations.  The  contraction  theory  denies  that  this 
loss  is  made  good  to  the  sun  from  without,  but  avers 
that  his  heat  is  kept  fully  up  to  his  standard,  whether 
that  standard  be  a  uniform  or  a  slightly  declining  one, 
by  the  falling  in  upon  himself  of  his  own  substance. 
In  other  words  —  the  absolute  loss  to  the  sun  of  heat  in 
almost  immeasurable  quantities  results  in  the  genera- 
tion by  contraction,  caused  by  this  very  loss,  of  nearly, 
if  not  quite,  equal  amounts  of  heat  without  perceptible 
diminution  from  age  to  age. 

This  subject  is  handled  by  R.  A.  Proctor  with  his 
usual  ability  in  a  letter  to  the  New  York  Tribune,  of 
December  26,  1884.  Though  I  have  not  the  paper  at 
hand,  I  recollect  that  he  takes  the  undeniable  position 
that  the  heat  rendered  sensible  by  the  sun's  contraction 
to  any  given  extent,  if  conserved,  is  exactly  the  same  in 
amount  that  would  be  required  to  expand  the  sun's 
volume  to  the  same  extent.  And  as  the  supposed  con- 
traction and  equal  expansion  would  be  simultaneous, 
there  could  be  neither  contraction  nor  expansion  in  vol- 
ume, and  neither  loss  nor  gain  of  heat  from  this  cause. 
In  other  words  —  if  the  sun's  heat  is  maintained  by  con- 
traction, that  same  heat  would  cause  an  equal  expansion; 


14  SOLAR    HEAT. 

consequently  there  would  he  no  contraction  and  no  heat 
generated  by  contraction.  The  theory  is  self -destructive. 

The  sun  cannot  contract  in  volume  except  by  an  ac- 
tual transference  of  his  heat  to  other  regions.  This  loss 
of  heat,  if  unrepleiiished  from  without,  would  leave  the 
whole  body  of  the  sun  a  loser  by  that  amount.  If  this 
loss  is  inconceivably  great,  the  sun's  cooling  down  must 
be  fearfully  rapid,  unless  the  loss  is  supplied  ab  extra. 

But  as  I  have  said—  we  have  no  evidence  that  he  is 
cooling  to  the  least  degree,  nor  that  he  is  contracting  to 
the  smallest  extent.  Indeed,  I  am  well  satisfied  that  no 
one  would  ever  have  suspected  the  sun  of  either  cooling 
or  contracting  at  the  present  time,  were  it  not  for  the 
necessity  for  accounting  in  some  way  for  the  apparently 
irreparable  waste  by  solar  radiation. 

Aggregations  of  matter  are  held  together  sometimes 
by  cohesion,  sometimes  by  chemical  action,  sometimes 
by  gravity,  and  sometimes  by  the  united  action  of  two 
or  more  of  these  forces.  We  are  not  now  inquiring  for 
the  nature  of  these  forces,  nor  whether  electricity  or 
magnetism  is  involved  or  not,  but  simply  recognize  the 
fact.  In  all  cases  heat  is  the  wedge  which  forces  the 
molecules  apart.  As  the  process  of  heating  advances, 
the  particles  are  separated  more  and  more  widely  by 
their  freer  and  longer  swings  back  and  forth.  As  the 
expansion  increases  there  is  more  room  for  molecular 
vibration,  and  an  increase  of  velocity  is  necessary  to 
enable  the  particles  to  make  the  longer  swings  in  equal 
times.  In  other  words :  There  is  an  increasing  capacity 
for  heat  as  heat  itself  increases.  This  effect  is  negative 
and  absorbs  a  part  of  the  heat  entering  the  body.  It 
does  not  cool  the  body,  but  slightly  retards  the  process 
of  heating. 


CONDENSATION    OR    SHRINKAGE.  15 

If  a  train  of  cars  should  be  gradually  retarded  in  its 
forward  motion  l>y  overloading  or  by  encountering  a 
rising  grade,  we  could  not  say  with  truth  that  it  had 
commenced  to  move  in  the  opposite  direction.  No 
more  can  we  say  that  a  body  that  is  constantly  becom- 
ing hotter,  though  at  a  diminishing  rate,  is  cooling  or 
becoming  colder. 

Vice  versa :  When  the  heat  of  a  highly  heated  body 
is  taking  its  departure,  either  by  radiation  or  conduction, 
the  causes  producing  condensation  reassert  themselves, 
and  the  body  contracts.  Pari  passu  with  this  contrac- 
tion, the  exact  reverse  of  what  we  have  seen  takes 
place.  The  particles  have  now  a  diminished  space  in 
which  to  vibrate ;  their  capacity  for  heat  is  diminished 
and  the  process  of  cooling  is  retarded  but  not  stopped ; 
much  less  is  the  opposite  process  of  heating  inaugurated 
by  cooling.  A  wide  distinction  is  to  be  observed  be- 
tween the  effect  of  contraction  by  the  loss  of  heat  and 
condensation  or  compression  by  the  application  of  ex- 
ternal force  without  any  such  loss.  In  the  latter  case 
there  will  be  a  rising  temperature.  In  the  former  there 
will  be  a  gradually  falling  temperature. 

It  is  this  semblance  of  heating  —  really  a  slight  re- 
tardation in  cooling  —  upon  which  the  advocates  of  con- 
traction as  the  source  of  the  sun's  heat  are  obliged  to 
rely  to  reimburse  him,  so  far  as  he  requires  reimburse- 
ment, for  all  the  heat  radiated  by  him  into  space,  esti- 
mated as  sufficient  to  warm  two  billion,  two  hundred 
million  such  worlds  as  ours. 

All  must  agree  that  so  long  as  the  temperature  of  the 
sun  remains  stationary,  the  amount  of  heat  received  and 
disbursed  will  be  equal,  to  a  fraction ;  none  will  be  lost 
by  expansion  or  gained  by  condensation,  for  neither  will 


16  SOLAK    HEAT. 

exist.  Therefore,  so  long  as  the  sun's  temperature  re- 
mains stationary,  the  amount  exported  is  precisely  equal 
to  the  amount  imported.  If  any  one  therefore  desires 
to  estimate  the  amount  of  the  sun's  imports  of  heat, 
whether. in  the  raw  or  manufactured  state,  all  he  has  to 
do  is  to  take  an  account  of  his  exports  of  the  same  com- 
modity. If  the  sun's  temperature  remains  unchanged 
and  he  sends  abroad  heat  enough  to  warm  2,200,000,000 
worlds,  then  he  receives  from  abroad  energy  in  some 
form  to  exactly  the  same  amount. 


CHAPTEK  III. 
POTENTIAL    ENERGY— ATMOSPHERIC    CONDENSATION. 

Creature  of  light  and  energy !  thy  way 

Is  through  the  unknown  void;  thou  hast  thy  throne 

Mornings  and  evenings  and  at  noon  of  day, 

Far  in  the  blue,  untended  and  alone. 

— PERCIVAL. 

POTENTIAL  ENERGY. 

BALFOUK  STEWART  and  P.  G.  Tait,  in  the 
"  Unseen  Universe,"  *  give  their  adhesion  to  the 
theory  that  the  solar  energy  is  "  running  down  "  in  the 
following  language :  "  But  while  the  sun  thus  supplies 
us  with  energy,  he  is  himself  getting  colder,  and  must 
ultimately,  by  radiation  into  space,  part  with  the  life- 
sustaining  power  which  he  at  present  possesses."  On  the 
following  page,  however,  they  assert  that  "the  present 
potential  energy  of  the  solar  system  is  so  enormous, 
approaching,  in  fact,  possibly  to  what,  in  our  helpless- 
ness, we  call  infinite,  that  it  may  supply  for  absolutely 
incalculable  future  ages  what  is  required  for  the  phys- 
ical existence  of  life."  This  is  loose  and  vague  in  the 
extreme.  They  do  not  inform  us  where  this  potential 
energy  resides,  nor  under  what  form  it  is  hidden.  We 
know  of  no  great  storehouse  of  potential  energy,  so 
called,  on  this  planet,  except  the  carbon  of  the  forests, 
the  coal  measures,  and  the  peat  beds,  and  they  could 
not  produce  the  heat  of  the  sun,  even  if  they  existed 
there. 

*  Pages  126  and  127. 
2  17 


18  SOLAR    HEAT. 

The  sun  is  without  doubt  a  vast  storehouse  of  unox- 
idized  matter  which,  by  combustion,  is  capable  of  giving 
out  an  immense  amount  of  heat,  if  such  combustion 
could  take  place  upon  a  theatre  as  cool  as  our  earth. 
But  in  the  sun  this  unoxidized  matter  is  already  heated 
to  a  temperature  far  beyond  that  at  which  combustion 
is  possible. 

If  these  learned  gentlemen  refer  to  the  possible  room 
for  further  solar  contraction  as  the  seat  of  this  "  poten- 
tial energy,"  adequate  to  the  "supply  for  absolutely 
incalculable  future  ages  of  what  is  required  for  the 
physical  existence  of  life,"  then  I  have  endeavored  to 
answer  this  theory  under  the  head  of  Condensation  or 
Shrinkage. 

There  is  no  reason  to  apprehend  that  the  particles  of 
matter  will  ever  wear  out ;  there  is  no  reason  to  believe 
that  they  will  lose  any  of  the  properties  they  now  pos- 
sess ;  there  is  no  reason  to  anticipate  that  the  forces  that 
now  operate  in  and  through  them  will  cease ;  and,  con- 
sequently, there  is  no  reason  to  believe  that  the  universe 
will  ever  run  down,  wear  out,  or  cease  to  move  forward 
as  at  present,  unless  by  a  fiat  of  Omnipotence. 

ATMOSPHERIC  CONDENSATION. 

Another  theory  is  that  of  W.  Matthieu  Williams, 
urged  with  great  learning  and  ingenuity  in  his  "Fuel 
for  the  Sun."  I  cannot  state  his  theory  more  briefly 
than  by  using  his  own  words,  first  prefixing  the  ques- 
tion of  Mr.  Grove,  to  which  the  passage  is  an  answer, 
thus: 

"What  becomes  of  the  enormous  force  thus  appa- 
rently non-recurrent  in  the  same  form?"  referring  to 
the  heat  radiated  into  space  by  the  sun  and  other  celes- 
tial bodies ;  to  which  Mr.  Williams  replies : 


ATMOSPHERIC    CONDENSATION.  19 

"So  far,  then,  I  answer  Mr.  Grove's  question  by 
showing  that  the  heat  radiated  into  space  by  each  of  the 
solid  orbs  that  people  its  profundities  is  received  by  the 
universal  atmospheric  medium;  is  gathered  again  by 
the  breathing  of  wandering  suns  who  inspire,  as  they 
advance,  the  breath  of  universal  heat  and  light  and  life ; 
then  by  impact,  compression  and  radiation,  they  concen- 
trate and  redistribute  its  vitalizing  power;  and  after 
this  work  is  done,  expire  it  in  the  wake  of  their  retreat, 
leaving  a  track  of  cool,  exhausted  ether — the  ash-pits 
of  the  solar  furnaces  —  to  reabsorb  the  general  radia- 
tions, and  thus  maintain  the  eternal  round  of  life."  * 
This  is  somewhat  poetical,  and  not  a  little  mixed,  but 
the  real  meaning  of  this  ingenious,  dashing  and,  on 
some  subjects,  rather  dogmatic  writer,  is  in  brief : 

1.  That  there  is  a  universal  atmosphere. 

2.  That  the  sun  is  constantly  (if  I  may  be  pardoned 
the  colloquialism)  butting  against  this  atmosphere  at 
the  rate  of  450,000  miles  per  day. 

3.  That  the  compression  produced  by  the  sun's  im- 
pact evolves  the  heat  of  the  sun. 

He  also  deals  largely  in  the  rollings,  tossings,  explo- 
sions, dashings,  clashings  and  flashings  of  the  alternately 
combining  and  decomposing  gases  in  the  sun's  atmos- 
phere. 

It  is  not  certain  that  chemical  changes  of  any  kind 
take  place  in  the  sun's  atmosphere.  In  the  lower  strata 
the  heat  is  certainly  too  intense  to  admit  of  chemical 
combinations.  It  is  possible  that  in  a  higher  and  cooler 
stratum  the  dissociated  gases  may  meet  and  combine, 
perhaps,  with  tremendous  explosions,  giving  out  great 
quantities  of  heat.  If,  for  example,  oxygen  and  hydro- 

*  Science  in  Short  Chapters,"  pages  81,  8-1,  and  85, 


20  SOL  AT?    HEAT. 

gen  in  this  stratum  combine,  they  will  form  water  or 
watery  vapor.  These  vapors,  being  heavier  than  their 
gases,  will  descend  to  a  lower  and  hotter  stratum,  where 
they  will  again  be  dissociated  and  rise  again  to  the 
stratum  of  recombination.  But  in  all  these  decomposi- 
tions and  recompositions,  not  the  smallest  quantity  of 
heat  is  gained  or  lost.  What  appears  to  be  gained  by 
combination  or  combustion  of  these  gases  is  lost  in  their 
decomposition  or  dissociation.  But  there  is  neither 
actual  gain  nor  loss,  except  what  appears  to  be  lost  by 
radiation  into  space.  This  grand  problem  of  the  im- 
mense loss  of  heat  to  the  sun  by  the  almost  inconceivable 
quantity  radiated  into  space,  and  apparently  lost,  our 
learned  and  ingenious  author  endeavors  to  solve  by 
means  of  the  universal  atmosphere  as  set  forth  in  X<». 
1,  2  and  3  above. 

On  these  I  would  simply  remark : 

1.  The   existence    of   the   universal    atmosphere    is 
assumed,    but   not   generally    conceded;    certainly    not 
proved. 

2.  If  any  atmosphere  much  more   dense  than  the 
impalpable  ether  tills  the   interstellar   spaces,   all    the 
movements  of  all  the  heavenly  bodies  would  be  steadily 
retarded  and  ultimately  destroyed. 

But  a  simple  illustration  will,  in  my  opinion,  dispose 
of  this  theory.  Imagine  a  concave  mirror  large  enough 
to  enclose  the  sun  and  his  proper  atmosphere,  for  accord- 
ing to  Mr.  Williams,  the  sun  has  an  atmosphere  of  his 
own.  Suppose  this  mirror  to  reflect  back  to  the  sun 
every  ray  of  heat  radiated  by  him.  as  well  as  exclude 
every  ray  approaching  him  from  without,  the  sun's  heat 
would,  of  course,  remain  absolutely  unchanged.  We 
ignore,  for  the  present,  any  supposed  supply  of  heat  by 


ATMOSPHERIC  CONDENSATION.  21 

contraction  of  the  sun.  Mr.  Williams  ignores  this  source 
entirely.  Now  open  the  windows  of  this  hollow  sphere 
both  before  and  behind  the  advancing  sun.  This  hypo- 
thetical universal  atmosphere  would,  of  course,  rush  in, 
and  an  equal  quantity  of  the  sun's  atmosphere  proper 
would  rush  out  of  the  windows  in  the  rear.  Would  this 
process  heat  or  cool  the  sun  8  That  would  depend 
wholly  on  whether  the  atmosphere  of  space  is  hotter  or 
colder  than  that  of  the  sun.  It  requires  no  prophet  to 
predict  the  result.  It  is  believed  by  all  that  the  atmos- 
phere of  space,  if  such  exists,  is  intensely  cold.  Remove 
the  imaginary  hollow  sphere  entirely,  and  give  the 
winds  full  sweep  on  all  sides,  and  the  blazing  atmos- 
phere of  the  sun  would  simply  be  swept  away  and  its 
place  supplied  by  one  colder  than  the  blasts  that  play 
around  the  north  pole  in  midwinter. 

On  this  theory  the  sun  would  change  his  whole  atmos- 
phere six  times  a  day,  or  once  every  four  hours.  Now 
it  is  well  known  that  owing  to  his  intense  heat,  his  atmos- 
phere is  composed  largely  of  metallic  gases.  As  these 
are  swept  out  into  the  cold  atmosphere  of  space,  they  will 
assume  in  turn,  first  the  vaporous,  then  the  liquid,  and 
finally  the  solid  form.  The  sun  would  then  be  a  verita- 
ble flying  shot-tower,  bombarding  space  with  literal  can- 
non balls  of  lead  and  iron.  Or  he  might  be  compared 
to  an  immense  rocket,  filling  his  wake  with  his  own 
wasted  substance. 

How  indefensible  this  theory  is  may  be  seen  at  a 
glance,  when  we  reflect  that  the  earth  moves  in  its  orbit 
nearly  four  times  as  fast  as  the  sun  is  supposed  by  this 
author  to  move,  and  yet  the  earth's  atmosphere  is  not 
swept  to  its  rear  and  left  in  its  wake.  Neither  is  the 
earth  set  on  fire  by  the  kk  impact  and  compression "  of 


22  SOLAR    HEAT. 

the  ''  universal  atmosphere  "  against  the  terrestrial  one. 
The  fact  is,  both  the  earth  and  the  sun  carry  their  atmos- 
pheres with  them.  If  this  hypothetical  universal  atmos- 
phere is  dense  enough  to  strike  fire  with  that  of  the  sun, 
as  flint  does  with  steel,  then  it  must  impede  and  retard 
the  motions,  not  only  of  the  sun,  but  of  all  heavenly 
bodies,  both  in  their  orbits  and  upon  their  axes.  It  will 
not  do  to  say  that  this  resistance  and  retardation  are  infi- 
nitesimal, while  we  demand  from  them  the  almost  infi- 
nite effects  of  providing  all  the  heat  that  warms  and 
vivifies  the  whole  realm  of  nature. 

It  is  hardly  necessary  to  add  that  the  doctrine  of  the 
virtual  eternity  of  the  universe  is  fatal  to  this  theory. 
If  this  retardation  has  been  in  operation  for  millions  of 
ages  the  heavenly  bodies  would  long  ago  have  come  to 
a  standstill.  I  repeat,  if  the  motion  of  the  sun  through 
the  universal  atmosphere  at  a  velocity  of  450,000  miles 
per  day,  according  to  Williams,  is  sufficient  to  kindle 
the  atmosphere  of  the  sun  into  a  tempest  of  fiame,  why 
should  not  the  same  effect  be  produced  by  the  motion  of 
the  earth  with  far  greater  velocity  through  the  same 
universal  atmosphere?  There  seems  to  be  no  escape 
from  this  dilemma.  Besides,  it  seems  not  to  have 
occurred  to  this  ingenious  writer  that  though  the  com- 
pressed atmosphere  in  front  of  the  sun,  if  there  be  such 
an  atmosphere  outside  of  the  sun's  atmosphere  proper, 
might  give  out  a  small  amount  of  heat  by  compression, 
it  would,  on  regaining  its  original  volume  by  its  elas- 
ticity, reabsorb  all  the  heat  given  out.  It  is  well  known 
that  the  collisions  of  elastic  bodies  give  out  almost  no 
heat;  their  arrested  motion  immediately  takes  new 
directions ;  in  fact,  their  motion  is  not  arrested  but  only 
changed  in  direction.  But  this  is  not  all.  This  hypo- 


ATMOSPHERIC    CONDENSATION.  23 

thctical  atmosphere  of  space,  mingling  witli  that  of  the 
sun,  would  be  raised  to  the  same  temperature,  and  with 
this  vastly  increased  temperature  thus  gained,  would  be 
left  behind  in  the  wake  of  the  sun,  thus  carrying  off 
vast  quantities  of  the  sun's  heat,  instead  of  adding  to  it. 


CHAPTER  IY. 

SIEMENS'  NEW    THEORY    OF    THE   SUN  —  CONVECTION 

CURRENTS  —  ENORMOUS  AMOUNT  OF  HEAT  EMIT- 

TED BY  THE  SUN  —  QUOTATIONS. 

Thy  path  is  high  in  heaven  :  —  we  cannot  gaze 

On  the  intense  light  that  girds  thy  car; 

There  is  a  crown  of  glory  in  thy  rays, 

Which  bear  thy  pure  divinity  afar, 

To  mingle  with  the  equal  light  of  star  ; 

For  thou,  so  vast  to  us,  art  in  the  whole 

One  of  the  sparks  of  night  that  fire  the  air, 

And  as  around  thy  centre  planets  roll, 

So  thou  too  hast  thy  path  around  the  central  soul. 

—  PEBCIVAL. 


eminent  savant,  Dr.  C.  W.  Siemens,  whose 
-L  death  the  scientific  world  has  lately  been  called 
upon  to  mourn,  assumes  as  the  basis  of  his  system, 
like  Prof.  Williams,  a  universal  atmosphere.  A  few 
quotations  from  an  article  by  him  in  the  Nineteenth 
Century  on  the  conservation  of  solar  energy*  will  give 
an  idea  of  his  theory  : 

"For  the  purposes  of  my  theory,  stellar  space  is  supposed  to  be 
filled  with  highly  rarefied  gaseous  bodies,  including  hydrogen,  oxy- 
gen, nitrogen,  carbon,  and  their  compounds,  besides  solid  materials 
in  the  form  of  dust." 

"In  this  case  pressures  would  be  balanced  all  around,  and  the 
sun  would  act  mechanically  upon  the  floating  matter  surrounding 
him  in  the  manner  of  a  fan,  drawing  it  toward  himself  upon  the 
polar  surfaces,  and  projecting  it  outward  in  a  continuous  disk-like 
stream  from  the  equatorial  surfaces." 

*  Republished  in  the  Eclectic  for  June,  1882,  p.  800. 
24 


SIEMENS     THEORY. 


FIG.  1.— DIAGRAM  ILLUSTRATING  SIEMENS'  THEORY. 


2f>  SOLAR    HEAT. 

"By  this  fan  action,  hydrogen,  hydrocarbons,  and  oxygen  are 
supposed  to  be  drawn  in  enormous  quantities  toward  the  polar  sur- 
faces of  the  sun ;  during  their  gradual  approach  they  pass  from  their 
condition  of  extreme  attenuation  and  intense  cold  to  that  of  com- 
pression, accompanied  with  increase  of  temperature,  until,  on  ap- 
proaching the  photosphere,  they  burst  into  flame,  giving  rise  to  a 
great  development  of  heat,  and  a  temperature  commensurate  with 
their  point  of  dissociation  at  the  solar  density.  ( ?)  The  result  of 
their  combustion  will  be  aqueous  vapor  and  carbonic  acid,  and  these 
products  of  combustion,  in  yielding  to  the  influence  of  centrifugal 
force,  will  flow  toward  the  solar  equator,  aud  be  thence  projected 
into  space." 

'-'  The  next  question  for  consideration  is,  What  would  become  of 
these  products  of  combustion  when  thus  returned  into  space  ?  Ap- 
parently they  would  gradually  change  the  condition  of  stellar  ma- 
terial, rendering  it  more  and  more  neutral ;(?)  but  I  venture  to 
suggest  the  possibility,  nay,  the  probability,  that  solar  radiation  will, 
under  these  conditions,  step  in  to  bring  back  the  combined  materials 
to  a  state  of  separation  by  dissociation  carried  into  effect  at  the  ex- 
pense of  that  solar  energy  which  is  now  supposed  to  be  irrevocably 
lost,  or  dissipated  into  space  as  the  phrase  goes." 

We  introduce  on  the  preceding  page  a  figure  from 
Dr.  Siemens  illustrating  his  theory. 

This  then  in  brief  is  Dr.  Siemens'  theory,  viz.:  start- 
ing at  the  equatorial  region  of  the  sun,  certain  com- 
pounds, mostly  gaseous,  are  thrown  out  by  the  rotary 
motion  of  the  sun  to  immense  distances — beyond  the 
orbit  of  the  earth,  as  he  elsewhere  states.  In  inter- 
stellar space,  these  compounds  are  decomposed  by  solar 
energy,  facilitated  by  extreme  attenuation  of  these 
compounds.  Being  now  reduced  to  their  elementary 
condition,  these  gases  descend  upon  the  polar  regions 
of  the  sun  and  there  unite  by  combustion,  giving  out 
the  heat  which  supplies  the  sun  in  perpetuity,  and, 
flowing  toward  the  equator,  are  again  projected  into 
space  in  a  ceaseless  round. 


27 

It  is  due  to  the  high  scientific  reputation  of  this 
writer,  as  well  as  to  the  eminent  scholars  who  have 
most  respectfully  criticised  this  theory,  that  we  should 
treat  it  with  similar  respect,  if  we  venture  to  criticise 
it  at  all. 

There  is  certainly  one  thing,  hinted  at  by  this  theory, 
highly  to  be  commended,  whether  the  author  had  a  dis- 
tinct conception  of  it  or  not,  and  I  shall  urge  it  here- 
after in  connection  with  another  theory  with  all  the 
earnestness  which  I  deem  its  importance  demands. 

This  is  that  none  of  the  heat  of  the  sun  is  so  radiated 
into  space  as  to  be  lost.  Dr.  Siemens  would  employ 
much,  if  not  all  the  heat  radiated  by  the  sun  into  space 
in  decomposing  the  gaseous  compounds  inhabiting  this 
space,  thus  charging  them  with  what  he  would  call 
potential  energy,  to  be  rendered  kinetic  on  their  return 
to  the  polar  regions  of  the  sun.  I  indorse  the  prin- 
ciple, not  the  application  of  it. 

We  will  now  note  a  few  objections  to  Dr.  Siemens' 
theory. 

1.  A   universal    atmosphere,   other    than    ether,    is 
not  yet  proved  to  the  satisfaction  of  scientists.     The 
astronomical  objections  to  the  existence  of   an  inter- 
stellar  resisting   medium  have  been  so  often  and   so 
fully  discussed  by  more   learned  writers,  that   I  will 
simply  note  the  objection  and  pass  on. 

2.  As  to  chemical  decomposition  of   gaseous  com- 
pounds in  space  :  Chemical  union  is  promoted  by  a  high 
temperature,  and  on  the  principle  of  similia  similibus 
curcmtur,  a  still  higher  temperature  results  in  chemical 
divorce.     Attenuation  of  gaseous  compounds  in  space 
may  favor  decomposition,  but  the  requisite  degree  of 
heat  is  totally  wanting.     Space  is  pervaded  by  solar 


28  SOLAR    HEAT. 

energy  in  the  form  of  ethereal  vibrations,  but  this 
energy  does  not  become  heat  until  it  meets  with  non- 
diatherinanous  matter.  I  know  of  no  reason  to  suppose 
chemical  decomposition  under  such  circumstances  to  be 
possible,  much  less  probable. 

3.  Dr.  Siemens  supposes  that  these  now  decomposed 
gases,  descending  upon  the  polar  regions  of  the  sun, 
would  burst  into  name  by  recombination,  thus  supply- 
ing the  heat  of  the  sun.     It  is  true,  that  if  currents  of 
inflammable  gases,  mixed  with  oxygen,  were  descending 
upon  the  SUITS  photosphere,  they  would  perhaps  for  a 
moment  combine,  but  the  next  moment  they  would  be 
decomposed,  as  all  agree  that  the  temperature  of  the  sun 
is  far  beyond  the  point  of  dissociation  for  all  chemical 
compounds.     These  supposed  gases  would  receive  heat 
from,  instead  of  communicating  it  to,  the  sun.      The 
gases  would  become  hotter,  but  the  sun  would  become 
colder  by  reason  of  this  hypothetical  gaseous  inundation. 

4.  But  suppose  we  concede  that  these  burning  gases 
would   communicate  heat  to   the   sun   instead  of   the 
sun  to  the  gases ;  still  the  fact  remains  that  a  continual 
round  of  chemical  decompositions  and  reunions  would 
simply  maintain  the  sun's  heat  unchanged,  without  gain 
or  loss.     Just  as  much  heat  would  be  lost  in  decomposi- 
tion  as  would   be   gained   by  reunion.      The  loss   by 
the   enormous   radiation   of  the  sun  is  wholly  unpro- 
vided  for    by   this   theory.      To    supply   this    loss   is 
the  problem  and  the  only  problem  in  the  case.     If  the 
sun's  radiations  were  discontinued,  he  would  need  no 
source  of  supply.     If   he  suffered   no  loss,   he  would 
require  no  reimbursement. 

5.  If  the  rigorous  logic  of  mathematics  would  admit  of 
matter  being  without  weight  or  even  weighing  less  thaii 


29 

nothing  at  the  sun's  equator,  so  that  it  would  actually 
leave  the  sun  for  extended  journeys  through  space,  this 
condition  would  apply  to  all  the  equatorial  matter  of 
the  sun,  and,  through  this,  to  the  whole  body,  which  is 
generally  regarded  as  gaseous.  We  should  then  have  the 
sun  himself  going  abroad  in  search  of  fuel  to  maintain 
the  solar  fires. 

6.  I  will  here  epitomize  what  seems  to  be  a  con- 
clusive answer  to  this  theory  from  an  article  by  R.  A. 
Proctor,  in  the  Cornhill  Magazine,  reproduced  in  the 
Eclectic  for  July,  1882,  page  30:  The  sun  revolves 
on  his  axis  in  twenty-five  days  and  his  velocity  at 
his  equator  is  1.25  miles  per  second,  or  4.41  times  that 
of  the  tangential  velocity  at  the  earth's  equator.  As 
centrifugal  force  increases  with  the  square  of  the  veloc- 
ity, this  force  at  the  sun's  equator  will,  ceteris  paribus, 
be  19.45  times  greater  than  at  that  of  the  earth.  But  it 
is  also  inversely  as  the  distance  from  the  center  of  the 
revolving  body. 

The  sun's  diameter  is  about  108  times  that  of  the 
earth,  so  that  his  equatorial  centrifugal  force,  as  com- 
pared with  that  of  the  earth,  is  19.45-4-108,  or  less  than 
one-fifth.  Not  only  this,  but  gravity  at  the  sun,  owing 
to  his  superior  mass,  is  at  least  twenty-seven  times  greater 
than  at  the  earth.  And  yet  matter,  whether  gaseous, 
liquid  or  solid,  manifests  no  tendency  to  leave  the  earth 
at  the  equator,  with  five  times  the  centrifugal  force  of 
the  sun,  and  weighs  but  slightly  less  there  than  at  any 
other  point  on  the  earth's  surface.  Proctor's  conclusion 
is  that  "  there  is  not  the  slightest  possibility  of  matter 
being  projected  into  space  from  the  sun's  surface  by 
centrifugal  tendency."  But  the  projection  of  gaseous 
compounds  into  space  by  the  sun's  equatorial  tangential 


30  SOLAR    HEAT. 

* 

force  is  the  corner  stone  of   Dr.   Siemens1   ingenious 
theory. 

SIR  WM.  THOMSON'S  THEORY  OF  CONVECTION  CURRENTS. 

The  last  explanation  of  solar  heat  to  which  I  will 
allude  is  the  Convection  Currents  of  Sir  Win.  Thomson. 
This  theory  supposes  the  main  body  of  the  sun  to  be  an 
intensely  heated  fluid  mass,  which,  by  the  convection 
currents  that  would  naturally  prevail,  is  continually 
turning  itself  inside  out,  or  bringing  the  interior  and 
more  highly  heated  portions  to  the  surface.* 

If  we  suppose  the  sun  to  be  an  intensely  heated  fluid 
mass,  which  no  one  doubts,  and  that  he  is  constantly 
cooling  at  his  surface  by  radiation,  as  would  certainly  be 
the  case,  if  his  heat  is  not  replenished  at  his  surface, 
then  convection  currents,  more  or  less  rapid,  would  cer- 
tainly prevail  from  the  interior  to  the  exterior  and  back. 
This  would  tend  to  equalize  the  temperature  through 
the  whole  mass.  The  result  would  be  the  gradual 
cooling  of  the  whole  mass  instead  of  the  surface  only. 
Whether  this  gradual  process  of  cooling  would  so  pro- 
long the  process  that  the  amount  would  be  absolutely 
imperceptible  for  the  period  of  nearly  5,000  years, 
during  which  the  race  has  cultivated  an  acquaintance 
with  the  sun,  is  a  question  which  I  do  not  feel  com- 
petent to  decide. 

One  thing  is  certain.  This  theory  only  professes  to 
prolong,  perhaps  indefinitely,  the  process  of  cooling  in 
the  sun.  But  it  must  fail  if  either  of  the  following 
propositions  be  true.  • 

1.  If  we  have  sufficient  evidence  on  which  to  decide 
that  the  sun  is  not  cooling  at  all,  or, 

*See  June  Eclfctic,  1882,  page  808. 


AMOUNT  OF  HEAT  EMITTED  BY  THE  SUN.      31 

2.  If  the  heat  given  out  by  the  sun  is  out  of  all  pro- 
portion to  the  gradual  cooling  supposed  by  this  theory. 
These  two  may  be  considered  together  under  the  follow- 
ing caption : 

ENORMOUS  AMOUNT  OF  HEAT  EMITTED  BY  THE  SUN. 

I  cannot  better  fortify  my  position  on  this  subject 
than  by  quoting  some  of  the  statements  of  distinguished 
scientists.  A  few  quotations  will  be  sufficient  for  my 
purpose,  and  if  they  tend  to  show  that  neither  the 
theory  of  "  Convection  Currents "  nor  any  of  the  pre- 
ceding ones  are  sufficient  to  account  for  the^  superlatively 
immense  quantities  of  heat  radiated  by  the  sun,  then  I 
shall  have  ample  apology  for  attempting  to  supply  the 
deficiency. 

I  will  first  quote  from  "The  Forces  of  Inorganic 
Nature,"  by  Dr.  J.  R.  Mayer,  page  264,  Youman's  Col- 
lection : 

'•  A  square  metre  of  our  earth's  surface  receives,  therefore,  accord- 
ing to  Pouillet's  results,  which  we  shall  adopt,  on  an  average,  in  one 
minute,  4,408  units  of  heat.  The  whole  surface  of  the  earth  is 
9,260,500  geographical  square  miles ;  consequently  the  earth  receives 
in  one  minute  2,247  billions  of  units  of  heat  from  the  sun.  In  order 
to  obtain  smaller  numbers,  we  shall  call  the  quantity  of  heat  neces- 
sary to  raise  a  cubic  mile  of  water  one  degree  C.  in  temperature,  a 
cubic  mile  of  heat.  Since  one  cubic  mile  of  water  weighs  408.54 
billions  of  kilogrammes,  a  cubic  mile  of  heat  contains  408.54  units  of 
heat.  The  effect  produced  by  the  rays  of  the  sun  on  the  surface  of 
the  earth  in  one  minute  is  therefore  5.5  cubic  miles  of  heat.  Let  us 
imagine  the  sun  to  be  surrounded  by  a  hollow  sphere  whose  radius 
is  equal  to  the  mean  distance  of  the  earth  from  the  sun,  or  20,589,000* 
geographical  miles,  the  surface  of  this  sphere  would  be  equal  to 
5,326  billions  of  square  miles.  The  surface  obtained  by  the  inter- 
section of  this  hollow  sphere  and  our  globe,  or  the  base  of  the  cone 
of  solar  light  which  reaches  our  earth,  stands  to  the  whole  surface 
of  this  hollow  sphere,  as  1  to  2,300  millions.  This  is  the  ratio  of  the 

*The  geographical  mile  =  7,420  metres;  the  English  mile  =  1,608  metres. 


32  SOLAR    HEAT. 

heat  received  by  our  globe  to  the  whole  amount  of  heat  sent  forth 
from  the  sun,  which  latter  in  one  minute  amounts  to  12,650  millions 
of  cubic  miles  of  heat. 

"This  amazing  radiation  ought,  unless  the  loss  is  in  some  way 
made  good,  to  cool  considerably  even  a  body  of  the  magnitude  of 
the  sun. 

"  If  we  suppose  the  sun  to  be  endowed  with  the  same  capacity 
for  heat  as  a  mass  of  water  of  the  same  volume,  and  its  loss  of  heat 
by  radiation  to  affect  uniformly  its  whole  mass,  the  temperature  of 
the  sun  ought  to  decrease  1.8  degrees  C.  yearly,  and  for  the  historic 
time  of  5,000  years,  this  loss  would  consequently  amount  to  9,000 
degrees  C." 

Again  I  quote  from  "  The  Sun,"  by  Prof.  Young, 
page  254 : 

"Since  there  is  every  reason  to  believe  that  the  sun's  radiation 
is  equal  in  all  directions,  it  follows  that  if  the  sun  were  surrounded  by 
a  great  shell  of  ice  one  inch  thick  and  186,000,000  miles  in  diameter,  its 
rays  would  melt  the  whole  in  the  same  time  (two  hours  and  thirteen 
minutes).  If  we  now  suppose  this  shell  to  shrink  in  diameter,  retain- 
ing, however,  the  same  quantity  oi'  ice,  by  increasing  its  thickness,  it 
would  still  be  melted  in  the  same  time.  Let  the  shrinkage  continue 
until  the  inner  surface  touches  the  photosphere,  and  it  would  consti- 
tute an  envelope  more  than  a  mile  in  thickness,  through  which  the 
solar  fire  would  still  thaw  out  its  way  in  the  same  two  hours  and 
thirteen  minutes,  at  the  rate,  according  to  Herschel's  determinations, 
of  more  than  forty  (nearer  fifty)  feet  a  minute.  Herschel  continues 
that  if  this  ice  were  formed  into  a  rod  45.3  miles  in  diameter,  and 
darted  toward  the  sun  with  the  velocity  of  light,  its  advancing  point 
would  be  melted  off  as  fast  as  it  approached,  if  by  any  means  the 
whole  of  the  solar  rays  could  be  concentrated  on  the  head.  Or,  td 
put  it  differently,  if  we  could  build  up  a  solid  column  of  ice  from 
the  earth  to  the  sun.  two  miles  and  a  quarter  in  diameter,  spanning 
the  inconceivable  abyss  of  ninety-three  million  miles,  and  if  then  the 
sun  should  concentrate  his  power  upon  it,  it  would  dissolve  and 
melt,  not  in  an  hour  nor  a  minute,  but  in  a  single  second ;  one  swing 
of  the  pendulum,  and  it  would  be  water;  seven  more,  and  it  would 
be  dissipated  in  vapor. 

"  An  easy  calculation  shows  that  to  procure  this  amount  of  heat 
by  combustion  would  require  the  hourly  burning  of  a  layer  of 


AMOUNT    OF    HEAT    EMITTED    BY    THE    SUN.  33 

anthracite  coal  more  than  sixteen  feet  thick  over  the  entire  surface 
of  the  suri. 

"It  is  equivalent  to  a  continuous  evolution  of  about  ten  thou- 
sand horse-power  on  every  square  foot  of  the  sun's  whole  area." 

I  will  indulge  in  only  one  more  quotation,  though 
they  might  be  multiplied  indelinitely.  This  from  Prof. 
Langley's  third  article  on  the  u  New  Astronomy,"  in 
the  December  Century,  1884,  page  234 : 

"  If  then,  the  whole  annual  orbit  of  the  earth  were  set  close 
with  globes  like  ours  and  strung  with  worlds  like  beads  upon  a  ring, 
each  would  receive  the  same  enormous  amount  the  earth  does  now 
(enough  to  raise  to  the  boiling  point  37,000,000,000  tons  of  ice  in  a 
minute). 

"  But  this  is  not  all;  for  not  only  along  the  orbit  but  above  and 
below  it  the  sun  sends  its  heat  in  seemingly  incredible  wastefulness, 
the  final  amount  being  expressed  in  the  number  of  worlds  like  ours 
that  it  could  warm,  which  is  2,200,000,000." 

It  would  seem  unkind  to  borrow  the  knight's  glitter- 
ing sword  to  slay  him  with,  and  doubly  so  to  borrow, 
the  brighter  thoughts  of  scientists  with  which  to  de- 
molish their  theories.  But  they  perform  this  service 
for  each  other  in  such  a  courtly,  I  had  almost  said,  lov- 
ing manner,  that  it  is  almost  a  pleasure  to  be  cut  to 
pieces,  and  a  high  honor  to  be  allowed  to  furnish  the 
weapons. 

Each  of  the  three  distinguished  authors  last  quoted 
holds  to  one  or  other  of  the  foregoing  theories. 

Some  may  be  disposed  to  think  that  this  very  brief 
review  of  theories  on  which  so  much  labor,  by  scholars 
so  eminent,  has  been  expended,  is  a  flippant  mode  of 
disposing  of  them.  I  should  certainly  plead  guilty  to 
the  charge  if  I  had  proposed  to  give  them  an  ex- 
haustive examination.  To  do  so  would  involve  time, 
space  and  research  that  I  do  not  command.  Neither  is 


34  SOLAR    HEAT. 

it  at  all  necessary.  The  advocates  of  one  theory  are 
necessarily  the  opponents  of  all  the  others,  and  thus 
the  authors  of  these  various  theories  have,  with  equal 
learning  and  courtesy,  done  ample  justice  to  each 
other's  theories. 

I  will  close  my  notice  of  these  theories  with  this 
remark : 

Four  of  them,  counting  the  greatest  numbers  of  ad- 
herents, viz.:  the  Meteoric,  the  Contraction,  the  Poten- 
tial Energy,  and  the  Convection  Current  theories,  all 
depend  in  the  last  resort  upon  gravitation.  They  claim 
that  gravitation  is  the  source  of  solar  heat,  but  fail  to 
tell  us  what  is  the  source  of  gravitation.  To  refer  solar 
heat  to  gravitation  and  there  rest,  is  like  resting  the 
world  on  the  back  of  a  huge  tortoise,  without  providing 
a  resting  place  for  the  latter.  If  gravitation  is  the 
source  of  solar  heat,  then  this  force  is  being  exhausted 
and  requires  constant  reimbursement.  This  same  heat 
should  directly  or  indirectly  refund  to  gravitation  all 
the  energy  borrowed  from  it.  Nature  has  no  bank- 
ruptcy laws.  She  is  inexorable  in  her  exactions.  All 
debts  must  be  paid  in  the  coin  of  Nature's  realm. 
This  coin  is  now  called  energy.  It  never  wears  out  by 
abrasion.  It  never  expands  nor  contracts  in  volume. 
It  is  never  hoarded  nor  hidden.  It  never  goes  out  of 
circulation.  No  part  of  it  can  possibly  be  lost,  and  no 
power  but  Omnipotence  can  add  to  it.  It  is  Protean  in 
its  manifestations,  but  one  in  essence. 

These  four  theories,  therefore,  all  depending  on  grav- 
itation, though  widely  diverse  in  other  respects,  share 
a  common  infirmity.  They  fail  to  complete  the  cir- 
cuit, and  consequently,  by  the  admissions  of  their 
authors,  furnish  to  the  sun  only  a  waning  supply  of 


AMOUNT    OF    HEAT    EMITTED    BY    THE    SUN.  35 

light  and  heat,  doomed  to  final  extinction  in  darkness 
and  death. 

The  other  two  theories  noticed,  and  which,  with  the 
foregoing,  comprise  all  that  have  commanded  the  re- 
spectful attention  of  scientists,  are  those  of  W.  Mathieu 
Williams  and  Dr.  C.  W.  Siemens.  These  both  depend 
upon  the  existence  of  a  hypothetical  universal  atmo- 
sphere. With  all  respect  for  their  distinguished  authors, 
I  cannot  but  regard  the  foundation  as  gassy  and  the 
superstructures  as  gauzy.  Mr.  Williams  makes  solar 
heat  to  arise  from  the  arrested  motion  of  the  sun's 
atmosphere,  backed  by  the  sun  himself,  impinging 
against  this  universal  atmosphere,  forgetting  that  all 
the  energy  thus  supposed  to  be  invested  by  the  sun  in 
the  form  of  heat,  must  be  deducted  from  his  translator^ 
and  rotary  motions.  Dr.  Siemens'  theory  relies  upon  a 
degree  of  centrifugal  force  at  the  sun's  equator  which 
Proctor  has  shown  does  not  exist,  and  upon  a  system 
of  solar  chemistry  which  is  purely  hypothetical  and 
which  could  not  add  one  iota  to  the  sun's  heat,  if  its 
existence  were  conceded. 


CHAPTER  Y. 

A  XEW  THEORY  OF  SOLAR  HEAT  — DIFFUSION  — EQUAL- 
IZATION —  CONSERVATION  —  TRANSFORMATION. 

I  stood  upon  the  hills,  when  heaven's  wide  arch 
Was  glorious  with  the  sun's  returning  march. 
And  woods  were  brightened,  and  soft  gales 

Went  forth  to  kiss  the  sun-clad  vales.' 

—LONGFELLOW. 

HAYING  examined  as  candidly  and  as  carefully  as 
Ave  are  able  all  the  principal  theories  advanced 
in  explanation  of  solar  heat,  and  being  unable  to  find  in 
any  one  of  them  a  satisfactory  explanation,  we  beg  to 
lay  them  all  aside  provisionally,  not  as  disproved,  but  in 
order  to  make  room  for  just  one  more. 

If  the  theories  examined  are  as  unsatisfactory  to  the 
reader  as  to  the  writer,  there  remains  only  an  aching 
void  for  a  new  one,  which  it  would  be  unkind  to  with- 
hold, since  the  material  is  so  abundant,  being  in  most 
cases  "  such  stuff  as  dreams  are  made  of,"  and  ypt  in  our 
day  dreams  we  sometimes  catch  glimpses  of  thoughts 
that  lead  us  into  the  very  presence  of  truth. 

It  is  our  duty  to  build  with  the  solid  blocks  of  knowl- 
edge on  foundations  that  cannot  be  shaken  —  build 
so  far  as  our  materials  will  extend,  and  if  then  we 
choose  to  construct  " castles  in  air"  no  harm  is  done, 
provided  we  label  them  truly.  Some  of  them  may  pos- 
sibly turn  out  to  be  the  simulacra  of  the  upper  domes 
of  the  true  temple,  but  most  of  them  are  doomed  to 
vanish  — 

36 


A    NEW    THEORY    OF    SOLAR    HEAT.  37 

"Into  thin  air, 

And  like  the  baseless  fabric  of  a  vision, 
The  cloud-capped  towers,  the  gorgeous  palaces, 
The  solemn  temples,  the  great  globe  itself, 
Yea,  all  which  it  inherit,  shall  dissol\re, 
And  like  an  insubstantial  pageant  faded, 
Leave  not  a  rack  behind." 

But  before  announcing  a  new  theory  on  this  subject, 
I  will  premise  that  there  is  no  lack  in  the  quantity  of 
light  and  heat,  or  energy  convertible  into  light  and  heat 
in  existence,  necessary  to  supply  in  perpetuity  the  solar 
fires.  The  light  and  heat  emanating  from  our  sun 
alone,  no  part  of  which  has  been,  or  ever  can  be  lost,  is 
sufficient  for  all  his  needs,  if  it  could  only  all  be  returned 
to  its  source,  or  exchanged  for  equal  quantities  from 
other  sources.  Besides,  there  are  untold  millions  of 
other  suns,  probably  as  bountiful  dispensers  of  light  and 
heat  as  our  sun. 

The  problem  then  is  not  how  to  create  light  and  heat ; 
that  is  already  done  and  does  not  require  to  be  repeated. 
They  may  change  to  other  forms  of  energy,  but  can 
neither  be  destroyed  nor  re-created. 

Neither  is  the  problem  how  to  guard  against  the 
light  and  heat  wandering  off  into  inaccessible  regions,  or 
beyond  the  limits  of  the  universe;  they  cannot  go 
beyond  the  bounds  of  the  universe,  for  this  is  boundless. 
Besides,  they  are  conditions  or  states  of  matter,  ether 
included,  and  can  exist  only  where  matter  exists. 

To  speak  of  heat,  or  any  other  forms  of  energy  as 
travelling  beyond  the  limits  of  the  material  universe,  is 
the  same  as  to  speak  of  its  travelling  into  non-existence, 
which  conservation  forbids. 

The  real  problem  is,  How  are  the  light  and  heat  given 


38  SOLAR    HKAT. 

out  by  the  sun,  or  an  equivalent  for  the  same,  reconcen- 
trated  in  that  luminary  ( 

DIFFUSION  -  EQUALIZATION. 

The  difficulty  in  explaining  this  reconcentration  is 
enhanced  by  the  well  known  tendency  of  heat  toward 
diffusion  and  equalization.  For  example:  Take  any 
number  of  iron  discs,  such  as  grocers  use  to  weigh 
our  sugar  and  coffee  with ;  heat  one-half  of  them  to  a 
white  heat,  and  let  the  other  half  be  stone  cold.  Now 
pile  them  into  a  stack  of  alternately  hot  and  cold  discs. 
In  a  few  hours,  if  excluded  from  all  commnni cation 
with  outside  matter,  they  will  be  found  to  be  all  of  one 
uniform  temperature.  This  is  but  a  single  example  of 
what  is  going  on  ceaselessly  in  all  forms  of  matter. 

All  bodies  are  in  constant  vibration.  Relatively  cold 
bodies  give  out  little  and  receive  much;  relatively 
heated  bodies  give  out  much  and  receive  little ;  all  tend 
toward  an  equilibrium.  The  greatest  of  all  levellers  is 
the  all-embracing  ether.  This  is  constantly  conveying 
away  the  light  and  heat  of  countless  suns,  but  whither  1 

Though  the  ether  is  the  greatest  equilibrator  of  heat, 
it  is  efficiently  aided  by  every  mass  and  every  molecule 
of  matter  in  the  universe.  These  masses  and  molecules 
avail  themselves  of  every  possible  mode  of  conveyance  — 
radiation,  conduction  and  convection  —  by  means  of 
which  to  equalize  the  one  constant  and  unvarying  stock 
of  heat  or  molecular  motion  in  the  universe.  Heat  may 
change  to  other  forms  of  energy,  but  the  law  of  univer- 
sal diffusion  changes  not. 

How  then  is  it  that,  with  infinite  ages  in  which  to  do 
their  work,  all  these  combined  and  tireless  agencies, 
working  in  concert,  make  absolutely  no  progress  in 


DIFFUSION EQUALIZATION.  39 

equalizing  this  one  constant  unchanging  stock  of  heat  ? 
Our  9ini  and  douhtless  all  the  suns  remain  fiery  centres 
of  intensest  heat  from  age  to  age.  The  earth,  large  por- 
tions of  which  are  always  locked  in  fetters  of  ice  and 
snow,  maintains  its  relative  temperature  with  equal  per- 
sistence. Why  is  it  that  equalization  on  the  hroadest  scale 
is  sleeplessly  at  work  with  all  the  agencies  of  nature  at  its 
command,  and  all  the  ages  in  which  to  do  its  work,  and 
still  makes  absolutely  no  progress  ? 

Not  only  do  all  the  agencies  of  nature  stand  ready 
to  lend  their  aid  in  the  work  of  diffusion,  but  the  heated 
bodies  themselves  seem  most  impatient  to  be  rid  of  their 
apparently  unwelcome  guest.  The  sole  business  of  our 
sun,  and  of  every  sun,  seems  to  be  the  flooding  of  the 
heavens  with  their  light  and  heat.  In  like  manner 
every  object  heated,  either  by  natural  or  artificial 
means,  makes  haste  to  part  company  with  its  heat. 
What  becomes  of  all  this  heat?  The  earth  is  not  becom- 
ing hotter.  It  is  highly  improbable  that  other  planets 
are  increasing  in  temperature.  The  universal  ether  is 
certainly  not  increasing  in  temperature.  It  is  incapable 
of  being  heated,  being  the  most  diathermanous  body  in 
existence.  Even  the  sun  is  not  becoming  hotter.  In 
the  opinion  6f  many  eminent  scientists  (already  spoken 
of)  the  temperature  of  the  sun  and  all  his  attendants  is 
declining  rather  than  increasing. 

This  cooling  of  the  sun,  however,  is  purely  hypo- 
thetical. So  far  as  observation  can  teach,  the  sun,  the 
earth,  and  all  celestial  bodies  preserve  an  apparently 
unvarying  average  of  temperature.  We  repeat  the 
question :  Whither  does  the  heat  of  -  our  sun  and  of  all 
the  suns  go  ? 

It  may  be  replied  that  the  ether  is  absolutely  infinite, 


40  SOLAR    HEAT. 

being  co-extensive  with  space,  arid  that  the  heat  of  our 
sun,  and  of  all  the  other  suns,  though  inconceivably 
great,  is  still  Unite  in  comparison  with  the  infinite  ether, 
and  that  this  infinite  ether  can  swallow  up  or  absorb 
any  finite  quantity  of  light  and  heat.  The  answer  is 
not  unanswerable,  because,  though  the  ether  is  infinite, 
so  is  the  number  of  the  solar  bodies  which  inhabit  it ; 
and  so,  also,  is  the  eternity  during  which  these  solar 
bodies  have  been  discharging  their  light  and  heat  into 
this  ethereal  ocean. 

The  ether  itself  cannot  be  said  to  have  any  degree  of 
positive  temperature,  but  it  has  in  the  highest  degree 
the  capacity  of  communicating  heat  from  one  body  to 
another. 

All  the  heat  thus  communicated  to  it  remains  in  the 
ether,  not  as  heat,  but  as  energy  convertible  into  heat, 
till  delivered  to  some  body  capable  of  receiving  it. 
This  energy  is  all  conserved ;  not  an  iota  is  lost.  But 
the  ether  is  not  becoming  more  highly  charged.  If  it 
were  we  would  soon  be  made  aware  of  the  fact.  If  the 
ether  had  been  loading  up,  so  to  speak,  for  ages  upon 
ages  past,  it  would  now  be  in  a  condition  to  make  not 
only  every  sun,  but  every  world,  enveloped  by  it,  a 
tophet  of  fire.  This  ether,  therefore,  must  have  as 
many  and  as  great  outlets  as  it  has  inlets  of  energy  rep- 
resenting heat.  Of  this  we  shall  speak  more  fully 
hereafter. 

What  we  wish  to  direct  attention  to  here  is  the  fact 
that  the  great  total  of  the  heat  everywhere  eagerly  seek- 
ing diffusion  and  equal  distribution  cannot  possibly  be 
conserved  continuously  in  the  form  of  heat.  If  so,  the 
constant  tendency  to  equalization  of  heat  which  we  have 
observed  would  long  ago  have  resulted  in  a  dead  level 


DIFFUSION  —  EQUALIZATION.  41 

of  equal  distribution.  When  that  condition  arrives,  if 
ever,  not  a  leaf  will  stir  —  nay,  not  a  leaf  will  exist. 
Matter  might  exist,  but  all  motion  and  all  life  and 
activity  would  be  at  an  end. 

What  then?  Can  we  deny  the  fact  of  the  universal 
diffusion  of  heat  which  we  see  going  on  both  in  the 
heavens  and  in  the  earth  ?  By  no  means.  This  cannot 
be  denied.  But  there  is  another  process,  invisible  to 
the  eye  and  masked  to  all  the  senses,  revealing  itself 
only  to  the  reason,  going  on  just  as  ceaselessly.  This  is 
the  transformation  of  heat  into  other  forms  of  energy. 
Heat,  as  such,  is  constantly  dying  out.  But  it  dies  as 
the  seed  does,  on  being  committed  to  the  ground,  to 
reappear  in  new  and  wonderful  forms. 

Our  earth  is  a  most  admirable  point  of  observation 
to  note  what  is  going  forward  in  all  directions  in  the 
heavens.  When  the  point  we  occupy  is  turned  toward 
the  sun,  we  receive  his  warm,  if  not  scorching,  beams, 
and  gain  an  idea  of  what  is  transpiring  at  his  surface. 
On  the  contrary,  when  our  antipodes  are  basking  in 
the  sun,  we  have  the  whole  hemisphere  of  the  heavens 
arching  over  our  heads.  What  do  we  receive  from 
this?  Only  the  faintest  and  feeblest  twinkling  light, 
and  no  appreciable  heat  whatever.  Why  should  we 
not  receive  as  much  light  and  heat  from  the  stars  as 
from  the  sun?  It  will  be  said  that  they  are  at  such 
immense  distances  from  us  that  almost  all  their  heat  is 
lost  to  us  by  dispersion.  But  if  each  fixed  star  is  a  sun, 
and  they  are  infinite  in  numbers  —  sunk  in  space  beyond 
telescopic  reach  —  and  especially  if  they  have  had  ages 
in  which  to  saturate  the  ether  with  light  and  heat,  then, 
notwithstanding  their  distance,  they  ought  to  make  our 
nights  as  light  and  as  hot  as  our  days.  That  they  do 


4-2  SOLAR    HEAT. 

not  seems  to  be  proof  conclusive  that  their  light  and 
heat  have  assumed  other  forms  of  energy.  The  energy 
is  all  conserved.  It  is  unimpaired,  but  masked  under 
other  forms.  But  why,  it  will  be  asked,  do  not  the 
emanations  from  our  sun  change  to  other  forms  of 
energy,  as  well  as  those  of  the  other  suns?  The 
answer  is  that  they  do.  The  rays  of  the  sun,  as  they 
reach  the  earth,  are  mainly  in  the  form  of  heat.  But 
when  they  have  penetrated  two  million  times  farther 
into  space,  as  the  light  and  heat  from  the  nearest  stars 
have  done  before  reaching  us,  it  is  not  improbable  that 
the  light  and  heat  from  our  sun  will  be  as  completely 
metamorphosed  as  are  the  emanations  from  those  other 
suns. 

The  one  point  that  I  desire  to  make  emphatic  in  this 
chapter  is,  that  neither  the  ether  that  fills  all  space,  nor 
the  globes,  great  and  small,  that  inhabit  this  ether,  are 
growing  hotter  by  reason  of  the  inconceivable  amount 
of  heat  poured  into  this  ether  by  all  the  suns. 

This  being  granted,  we  are  ready  for  another  step, 
which  follows,  as  it  seems  to  me,  with  the  certainty  of 
demonstration.  Thus :  If  all  the  heat  from  an  infinite 
number  of  stellar  suns  has  been  pouring  into  this  uni- 
versal ether  for  indefinite,  if  not  for  infinite  ages ;  if  it 
has  all  been  conserved  and  is  still  in  existence ;  if  there 
is  no  other  universal  ether  into  which  this  heat  can 
make  its  escape ;  if  neither  this  universal  ether  nor  its 
included  spheres  are  becoming  hotter  by  the  reception 
of  this  heat ;  then  it  seems  to  me  that  I  am  justified  in 
saying  that  this  heat  must  change  to  other  forms  and 
disguises.  The  forces  of  nature  masquerade  grandly ; 
sometimes  in  the  ineffable  light  and  heat  of  the 
sun,  sometimes  in  the  darkness  and  silence  of  night; 


DIFFUSION EQUALIZATION.  43 

but  none  the  less  real  in  the  latter  case  than  in  the 
former. 

If  it  be  asked  into  what  other  forces  heat  is  converted 
when  it  ceases  to  exist  as  heat,  I  answer,  into  all  the 
other  forms  of  energy.  Heat,  as  I  have  elsewhere 
observed,  is  the  primitive,  original,  unspecialized,  and 
all-embracing  form  of  energy  from  which  all  others  are 
derived. 


CHAPTER  VI. 

WHAT  IS  THE  TRUE  SOURCE  OF  SOLAR  HEAT? 
ILLUSTRATIONS  AND  ARGUMENTS. 

And  now  undirnmed,  unshrouded  on  the  high 
O'erbending  vault  of  sapphire,  as  an  eye, 
Soothing  the  brow  of  heaven,  it  pours  abroad 
Brightness  o'er  vale  and  mountain,  gilds  the  rock, 
Silvers  the  winding  river,  tips  the  wave 
With  flowing  amber,  where  its  foam  wreaths  lave 
The  ocean's* bulwark,  seeming  to  unlock 
The  pure  and  calm  benignity  of  God. 

—  PERCIVAL. 

THERE  is  a  true  doctrine  in  regard  to  solar  heat, 
whether  we  can  discover  it  or  not.  Let  us  at  least 
try. 

I  can  best  introduce  what  I  have  to  propose  by  a 
very  inadequate  comparison.  It  will  furnish  the  out- 
lines of  the  idea  and  the  imagination  can  easily  expand 
and  modify  it  to  suit  the  subject. 

All  that  will  be  required  is  the  Atlantic  Ocean,  or, 
if  that  cannot  be  spared,  an  equal  quantity  of  water, 
and  a  thousand  heated  cannon  balls.  Let  the  ocean  be 
so  neatly  enclosed  that  not  a  drop  of  water  nor  a  unit 
of  heat  can  be  added  or  subtracted,  except  as  here- 
inafter provided.  The  balls  we  will  suppose  to  be 
heated  to  212°  Farenheit  and  scattered  broadcast  upon 
the  bottom  of  the  ocean,  which  we  will  suppose  to  be 
of  fresh  water  congealed  to  ice.  We  will  suppose  that 
in  some  unexplained  way  these  one  thousand  cannon 
balls  are  kept  permanently  at  the  uniform  tempera- 


WHAT    IS   THE    TRUE    SOURCE    OF    SOLAR    HEAT?          4:5 

tare  of  212°,  or  the  boiling  point  of  water.  What 
will  happen  \  The  balls  will  immediately  thaw  out 
little  pockets  around  themselves,  which  will  continue 
to  enlarge  until  they  meet  and  the  whole  ocean  will  be 
liquefied.  But  the  warming  process  will  not  stop  here. 
In  fact  it  will  never  stop  until  every  drop  in  the  ocean 
has  been  brought  into  contact  by  convection  currents 
with  some  of  the  balls  and  raised  to  the  boiling  point. 

We  can  now  dispense  with  the  secret  source  of  heat 
to  the  balls.  Henceforth  the  interchange  between  the 
water  and  the  balls  will  be  equal  and,  as  there  is  neither 
gain  nor  loss  to  either,  this  condition  would  remain 
unchanged  forever. 

We  will  now  transfer  the  scene  to  the  heavens.  The 
suns  are  scattered  in  the  ethereal  ocean  as  sparsely,  in 
proportion  to  size,  as  one  thousand  balls  would  be  in 
the  Atlantic  Ocean.  They  are,  in  some  as  yet  un- 
explained way,  kept  at  a  temperature  vastly  higher 
than  we  have  assigned  to  these  cannon  balls.  The 
ethereal  ocean  is  as  tightly  hemmed  in,  so  far  as  gain- 
ing or  losing  heat  is  concerned,  as  we  have  supposed 
the  Atlantic  Ocean  to  be.  The  reader  may  figure  to 
himself  the  universal  ethereal  ocean  as  large  as  his 
imagination  can  compass,  and  I  will  surround  it  on 
every  side  and  touching  it  at  every  point  of  its  peri- 
phery, with  other  ethereal  oceans  just  as  large,  from 
which  as  much  heat  will  constantly  be  entering  the  first 
as  is  escaping  from  it.  The  application  is  plain.  If 
the  suns  scattered  through  the  universal  ether,  however 
sparsely,  have  been  giving  out  heat  at  the  present  rate 
for  infinite  ages,  the  whole  ethereal  ocean  will  now  be 
in  a  condition  to  give  back  at  every  point  just  as  much 
heat  as  it  receives,  just  as  the  water  of  the  Atlantic 


4:6  SOLAR    HEAT. 

Ocean  at  212°  will  impart  to  every  ball  in  contact  with 
it,  just  as  much  heat  as  the  ball  imparts  to  the  water. 
In  other  words,  the  ether  imparts  to  the  suns  just  the 
same  amount  of  heat  that  the  suns  commit  to  the  ether. 

Of  course  the  comparison  between  an  ocean  of  water 
and  an  ocean  of  ether  is  very  imperfect.  The  former 
could  get  around  to  touch  the  balls  and  equalize  the 
temperature  only  by  slow  convection  currents,  involv- 
ing immense  periods  of  time,  while  the  impulses  com- 
mitted to  the  ether  are  transmitted  at  the  rate  of  nearly 
twelve  million  miles  a  minute.  Again,  water  commu- 
nicates heat  to  the  balls  and  the  balls  to  the  water  only 
by  conduction,  while  the  sun  sends  out  all  his  heat  by 
radiation  to  other  suns  and  receives  an  equal  amount 
from  other  suns  by  counter  radiation,  ether  being  the 
common  carrier  in  both  directions.  The  comparison 
fails  in  this  also.  The  ocean  being  once  brought  to  the 
boiling  point  would  remain  there,  independent  of  the 
balls;  that  is,  the  interchange  of  heat  would  go  on 
between  the  particles  of  the  water  and  the  balls  could 
be  dispensed  with  altogether.  Not  so  with  the  ether ; 
it  can  only  receive  heat  vibrations  from  and  can  only 
deliver  them  to  non-ethereal  matter. 

Another  notable  difference  is  this:  If  we  thrust 
our  hand  into  a  cistern  of  water  at  212°,  or  grasp  a 
cannon  ball  at  the  same  temperature,  AVC  experience  the 
same  sensation  of  heat  in  either  case.  But  if  we  could 
approach  the  sun  and  thrust  our  hand  into  the  lire 
clouds  that  compose  his  inner  envelope,  the  hand  would 
be  reduced  to  incandescent  gases  in  an  instant ;  and  yet 
our  whole  bodies,  often  very  chilly  at  that,  are  envel- 
oped in  the  same  ether  which  I  have  supposed  capable 
of  communicating  just  as  much  heat  to  the  sun  as  the 


WHAT    IS    THE    TKUE    SOUKCE   OF    SOLAR    HEAT?          4:7 

sun  communicates  to  the  ether.  This  seems  to  be  con- 
tradicted by  universal  experience.  We  are,  therefore, 
driven  to  the  adoption  of  one  of  two  alternatives.  One 
is  that  the  heat  dispensed  so  bountifully  by  our  sun,  and 
without  doubt  by  all  other  suns  that  inhabit  space,  grad- 
ually dies  out  and  disappears.  The  idea  that  this  heat 
wanders  beyond  the  coniines  of  the  universe,  we  have 
seen  to  be  absurd,  both  because  we  cannot  assign  boun- 
daries to  the  universe,  and  because  heat  is  a  condition 
of  matter,  being  matter  in  motion.  But  if  this  heat,  a 
most  conspicuous  form  of  energy,  dwindles  into  non- 
existence,  then  the  grandest  discovery  of  modern  times, 
the  conservation  of  energy,  disappears  with  it. 

The  other  alternative  is  that  heat  is  the  primal  and 
unspecialized  form  of  energy,  including  in  itself  all  other 
forms,  full  of  the^V^  of  youth,  embracing  in  itself  the 
"promise  and  potency"  of  all  the  forms  of  energy  that 
figure  in  heaven  and  earth. 

According  to  this  latter  alternative  the  general  or 
mixed  vibrations  which  produce  light  and  heat  do,  and 
necessarily  must,  at  certain  stages  of  their  progress  (for 
they  never  rest),  become  specialized  or  separated  into 
electricity,  magnetism,  gravitation,  chemical  action,  etc., 
without  losing  an  iota  of  quantity  or  efficiency.  It 
follows  with  equal  certainty  that  at  some  other  stage  of 
the  never  ending  progress  of  these  latter  forms  of 
energy,  they  must  again  be  despecialized  and  take  on 
the  general  form  of  heat.  Why  may  we  not  suppose 
this  last  change  to  take  place  at  the  solar  surfaces '.  We 
know  that  mechanical  motion,  one  of  the  special  forms 
of  energy,  turns  to  heat  on  being  arrested  or  impeded ; 
so  does  electricity;  so  do  the  chemical  molecular  con- 
cussions which  evolve  heat.  Analogy  would  lead  us  to 


48  SOLAR    HEAT. 

believe  that  all  the  forms  of  energy  with  which  the 
ether  is  freighted  will  turn  to  heat  at  the  surface  of  the 
sun,  provided  the  condition  of  the  solar  surface  is  such 
that  any  other  form  of  energy  is  there  an  impossibility. 
We  are  not  without  hints,  if  not  positive  proof,  that  all 
other  forms  of  energy,  unless  we  except  electricity,  are 
suspended  or  masked  in  the  heat-radiating  portion  of 
the  sun  and  merged  in  pure,  unmitigated  heat. 

Gravitation,  according  to  the  theory  hereinafter 
advanced,  is  simply  a  mechanical  force  coming  from 
every  point  in  the  celestial  concave  and  centring  on 
the  sun.  Of  course  it  is  to  be  expected  that  such  a 
force,  impinging  on  all  sides  of  the  sun  equally,  would 
be  arrested  or  stopped  and  changed  to  heat. 

In  short,  the  theory  of  solar  heat  here  adduced  is 
substantially  this :  All  the  suns  of  space,  blazing  with 
inconceivable  intensity  of  heat,  have  been  pouring  forth 
that  heat  by  radiation  into  the  ethereal  ocean  for  infi- 
nite ages.  Not  an  iota  of  all  this  heat  has  been  lost  or 
destroyed.  But  it  has  assumed  and  is  assuming  other 
forms,  else  the  ether  would  be  surcharged  with  ever- 
increasing  heat.  Not  only  does  this  heat  assume  other 
forms,  but  the  ethereal  ocean  must  have  exactly  as 
many  and  as  large  outlets  of  this  energy  as  it  has  inlets 
or  fountains  pouring  into  it.  Every  sun  is  a  "  hole  in 
the  sky,"  which  drinks  up  or  absorbs  just  as  much 
energy  from  the  ether  as  it  pours  into  it  by  radiation. 

Every  sun  is  a  consumer  as  well  as  a  producer,  a 
receiver  as  well  as  a  sender.  He  receives  vibrations  of 
mechanical  force,  electricity,  magnetism,  etc.  He  issues 
them  in  the  general  unsifted  form  of  radiant  light  and 
heat. 

This  process  is  not  wholly  without  an  analogue  on 


WHAT    IS    THE    TRUE    SOURCE    OF    SOLAR    HEAT?         49 

earth.  In  the  mills  of  Minneapolis  the  air  is  loaded 
with  impalpable  particles,  which  we  can  neither  see, 
feel,  hear,  taste  nor  smell,  and  which,  in  the  absence  of 
rire,  are  perfectly  harmless,  and  yet  on  lighting  a  match 
the  solid  stone  structures  have  been  blown  to  fragments. 
So  the  ethereal  undulations,  coming  from  the  stars,  that 
reach  our  earth  and  strike  upon  its  cold  sides,  may 
undergo  no  change,  while  the  same  undulations,  arriv- 
ing in  broadsides  upon  the  sea  of  lire  composing  the 
sun's  surface,  may  turn  to  like  lire  and  be  again  radi- 
ated as  heat,  and  so  on  forever.* 

The  ethereal  ocean  is  full  of  heat  or  the  elements  of 
heat ;  not  as  an  egg  is  full  of  meat ;  not  as  an  ocean  is 
full  of  water;  not  as  the  space  immediately  surround- 
ing our  planet  is  full  of  air ;  but  full  according  to  the 
peculiar  nature  and  functions  of  this  wonderful  medium. 

It  is  simply  an  impossibility  that  the  universal  ether, 
broad  as  it  is,  should  not  be  full,  or  saturated  to  over- 
flowing, with  the  undulations  of  heat  that  have  been 
poured  into  it  by  radiations  from  countless  millions  of 
suns  during  infinite  ages,  if  they  are  all  in  some  form  con- 
served. But  where  can  we  find  room  for  this  overflow? 
Nowhere  in  heaven  or  earth,  except  into  these  same 
heat-devouring  suns,  which  require  daily  and  hourly 
exactly  the  same  quantity  of  energy  radiated  by  them 
to  supply  the  loss  caused  by  this  radiation. 

When  the  sea  or  the  saturated  ground  is  full  of 
water,  it  overflows  by  evaporation  into  the  upper  air. 
When  the  upper  air  in  turn  becomes  supersaturated,  it 
overflows  upon  the  sea  and  land.  So  with  the  ether  and 
the  included  suns.  The  suns  supply  the  ether  and  the 

*  Daniel' s  "  Physics,"  page  4*3. 


50  SOLAR    HEAT. 

•ether  supplies  the  snns.  Since  the  dawn  of  creation 
heat  has  been  undergoing  transformations  and  retrans- 
formations,  but  neither  annihilation  nor  re-creation. 

This  theory  fully  answers  the  question  asked  in  Chap- 
ter Y:  "Why  is  it  that  equalization  on  the  broadest 
scale  is  sleeplessly  at  work  with  all  the  energies  of 
nature  at  its  command  and  all  the  ages  in  which  to  do 
its  work,  and  still  makes  absolutely  no  progress.'1  The 
answer  is  that  heat  as  heat  is  not  becoming  universally 
diffused.  On  the  contrary,  as  heat,  it  is  constantly 
dying  out,  only  to  reappear  in  other  forms  of  energy. 
In  some  form  of  energy  it  is  undergoing  constant  dif- 
fusion, but  diffusion  includes  motion  in  all  directions, 
toward  the  suns  as  well  as  from  them.  But  heat 
changed  to  mechanical  motion,  and  other  forms  of 
energy,  does  not  retain  these  new  forms  forever,  but  is 
constantly  changing  back  to  heat  at  the  solar  surfaces  in 
an  eternal  round.  The  ethereal  waves  pass  the  earth 
coldly  by,  because  there  is  nothing  in  the  circumstances 
at  the  earth  compelling  a  change  of  form.  They  turn 
to  heat  at  the  sun.  because  that  is  the  only  form  of 
energy  possible  in  the  sun. 


CHAPTEK  VII. 

SOLAR  HEAT,  CONTINUED  — FURTHER  ILLUSTRA- 
TIONS AND  ARGUMENTS. 

•     We  court  thy  beams,  great  majesty  of  day, 
If  not  the  soul,  the  regent  of  the  world, 
First  born  of  heaven  and  only  less  than  God. 

— ARMSTRONG. 

IT  may  be  alleged  that  the  sun  is  gradually,  though 
imperceptibly,  cooling  down,  and  that  this  cooling 
process  accounts  for  all  the  heat  given  out  by  the  sun, 
but  never  returned.  We  might  admit  the  possibility  .of 
the  first  clause  of  this  allegation,  the  gradual  cooling, 
while  denying  the  second.  I  passed  in  my  summer 
rambles  this  year  the  mill  to  which  I  used  to  carry 
grists  when  a  boy,  fifty  years  ago.  The  pond  is  as 
full  to-day  as  it  was  then.  If  a  man  had  attempted  to 
convince  me  that  not  a  drop  of  water  had  entered  this 
pond,  though  the  mill  had  been  running  for  a  half  cen- 
tury, and  that  the  water  now  running  through  the  mill 
as  swiftly  as  formerly  was  only  the  residue  of  what 
was  in  the  pond  fifty  years  ago,  I  should  have  been 
obliged  to  consider  him  a  lunatic  or  a  liar. 

It  would  be  a  grotesque  comparison  —  that  of  a  mill 
pond  with  the  sun  —  and  yet  there  is  one  respect  in 
which  all  will  recognize  the  resemblance.  A  pond  con- 
tains a  definite  quantity  of  water,  and  if  a  gallon  should 
be  removed  and  none  be  added,  the  pond  would  thence- 
forth contain  a  gallon  less.  The  whole  body  of  the 

5} 


52  SOLAK    TIEAT. 

sun,  also,  is  pervaded  by  a  certain  definite  quantity 
which  we  call  heat,  "If  we  should  build  up  a  solid 
column  of  ice  from  the  earth  to  the  sun,  two  miles  and 
a  quarter  in  diameter,  spanning  the  inconceivable  abyss 
of  ninety -three  million  miles,  and  if  then  the  sun  should 
concentrate  his  power  upon  it,  it  would  dissolve  and 
melt,  not  in  an  hour  nor  a  minute,  but  in  a  single 
second."  Multiply  this  by  the  minutes,  hours,  days, 
years,  and  millions  of  years  during  which  it  is  believed, 
if  not  known,  that  the  sun  has  been  radiating  heat  at 
this  rate,  and  we  shall  gain  some  idea  of  the  heat  lost 
by  the  sun,  if  there  has  been  no  return.  Every  second 
the  sun  is  poorer  in  heat  by  this  amount,  if  none  has 
been  returned  to  it.  Can  even  philosophers  persuade 
themselves  that  the  heat  now  radiating  from  the  sun  is 
only  the  residue  of  that  possessed  by  him  five  thousand 
years  ago? 

It  would  seem  to  be  an  abuse  of  all  sound  reasoning 
to  say  that  such  an  expenditure  of  heat  by  the  sun,  for 
thousands  of  years,  and  probably  for  long  ages,  results 
only  in  an  imperceptible  cooling  of  the  sun. 

Professor  Newcomb,  in  his  "  Popular  Astronomy," 
page  518,  estimates  a  probable  loss  of  from  five  to  ten 
degrees  per  annum,  and  adds:  "It  would,  therefore, 
have  entirely  cooled  off  in  a  few  thousand  years  after 
its  formation,  if  it  had  no  other  source  of  heat  than  that 
shown  by  its  temperature." 

But  great  as  is  the  sun's  daily  and  hourly  expendi- 
ture of  heat  by  radiation,  no  one  doubts  but  that  an 
infinite  number  of  other  suns  are  daily  and  hourly  radi- 
ating heat  at  a  similar  rate.  All  these  radiations  of  all 
these  suns  are  into  one  common  ether,  which  has  no 
power  to  hide  or  destroy,  but  only  to  transmit  the  same. 


ILLUSTRATIONS    AND    ARGUMENTS.  53 

Is  it  not  more  reasonable  to  believe  that,  in  some  one 
or  more  of  the  forms  or  disguises  that  physical  force  is 
capable  of  assuming,  this  ether  transmits  the  same  from 
sun  to  sun  in  equal  exchange,  than  to  suppose  that  all 
this  energy  is  going  out  of  existence  ?  This  could  not, 
of  course,  be  admitted  for  a  moment.  But  if  all  the 
heat  issuing  from  all  the  suns  that  stud  the  firma- 
ment and  extend  to  infinity  is  conserved,  where  can  it 
possibly  be  borne,  if  not  to  these  same  suns  in  endless 
exchange  ? 

All  ethereal  undulations  start  from  non-ethereal 
senders,  and  are  transmitted  to  non-ethereal  receivers, 
or  to  —  nowhere.  Where  can  the  ether  lind  in  space 
material  receivers  of  its  undulations,  if  we  exclude  all 
material  bodies  inhabiting  space,  except  such  planets, 
rings  and  satellites  as  may  revolve  around  individual 
suns  ?  These  last  probably  do  not  absorb  more  than  one 
two  hundred  and  thirty  millionth  part  of  the  heat  radi- 
ated from  their  respective  suns,  and  the  whole  of  that  is 
returned  to  this  same  ether,  as  these  minor  bodies  are 
not  becoming  hotter ;  so,  if  the  suns  do  not  receive  heat 
from,  as  well  as  radiate  it  into,  the  all-enveloping  ether, 
then  the  ether  itself  must  be  the  sole  repository  of  all 
the  radiations  from  all  the  suns. 

The  ether  is  not  a  reservoir  which,  when  fulJ,  will 
overflow,  but  it  is  a  vibrating  medium  capable  of  such 
a  state  of  vibration  as  existed  in  the  nebular  ages,  when 
the  universal  realms  of  space  were  pervaded  by  such  a 
degree  of  heat  as  to  maintain  every  kind  of  matter  in 
the  form  of  incandescent  gases  expanded  so  as  to  be  co- 
extensive with  space.  If  this  ether  is  now  and  for  ages 
past  has  been  receiving  the  heat  radiations  from  all  the 
suns,  and  returning  none,  we  ought  now  to  be  in  the 


54  SOLAR    HEAT. 

midst  of  a  new  nebular  era  from  the  accumulated  heat 
of  ages. 

If  the  nitrogen  of  our  atmosphere  were  suddenly 
replaced  with  carburetted  hydrogen,  and  one  of  the 
inhabitants  of  the  earth  should  survive  the  universal 
suffocation  that  would  ensue  long  enough  to  strike  a 
match,  the  earth  would  almost  instantly  be  wrapped  in 
an  ocean  of  flame.  The  ether  of  space  is  not  an  inflam- 
mable gas,  or  mixture  of  gases,  that  can  be  turned  to 
flame  even  by  the  intense  heat  of  the  sun.  But  I 
submit  that  the  condition  of  the  ethereal  vibrations 
before  reaching  the  sun  may  be  as  different  from  the 
vibrations  of  this  same  ether  after  reaching  the  sun,  as 
would  be  the  condition  of  an  atmosphere  of  oxygen  and 
carburetted  hydrogen  before  and  after  the  application  of 
a  match. 

Considering  for  the  moment  the  transmission  of  light 
and  heat  under  the  figure  of  a  current,  this  current 
cannot  forever  flow  outwardly  from  the  sun,  without  a 
corresponding  influx  through  the  same  or  some  other 
channel.  But  there  is  no  other  channel  or  medium  for 
the  influx  of  energy  to  the  sun  but  this  self-same  ether. 
The  earth  is  a  way-station  on  this  thoroughfare  for  the 
passage  of  streams  (to  continue  the  figure)  of  energy 
passing  in  both  directions,  outwardly  from,  and  inwardly 
to,  the  sun.  The  outgoing  rays  (to  use  the  correct 
term)  reach  us  in  the  form  of  solar  light  and  heat.  The 
incoming  rays,  on  the  return  voyage,  reach  and  pass  our 
mundane  station  in  forms  unrecognizable  by  any  of  our 
senses,  as  unlike  the  rays  that  reach  us  from  the  sun 
direct  as  an  atmosphere  of  oxygen  and  carburetted 
hydrogen  would  be  unlike  an  atmosphere  of  flame. 

This  comparison  is  sufficient  to  show  the  possibility 


ILLl  STKATIONS    AND    ARGUMENTS.  55 

of  ethereal  vibrations  before  reaching  the  sun,  being  as 
cold*  as  those  we  receive  from  the  scintillating  stars  on 
a  winter  night,  and  yet  capable  of  producing  the  intense 
heat  of  the  rays  of  a  mid-summer  sun.  But  something 
more  than  a  possibility  is  wanted;  in  fact,  a  positive 
demonstration  is  demanded.  One  demonstration,  how- 
ever, ought  to  be  sufficient,  and  a  demonstration  such 
as  the  nature  of  the  case  admits  ought  to  be  satisfac- 
tory to  candid  and  reasonable  minds. 

Let  us  see  if  we  can  reach  such  a  demonstration  of 
the  proposition  that  the  same  ether  which  transmits  the 
radiant  energy  of  heat  in  all  directions  from  the  sun, 
also  transmits  to  the  sun  an  exactly  equal  amount  of 
energy  from  other  suns  and  celestial  bodies  in  forms 
capable  of  being  changed  to  heat  at  the  sun. 

We  premise  that  Nature,  in  her  grand  and  unim- 
peded operations,  suffers  absolutely  neither  loss  nor 
gain.  Every  exhibition  of  motion  or  force  is  equal  to 
that  which  precedes  and  that  which  follows.  A  given 
quantity  of  the  cold  and  specialized  rays  that  reach  the 
sun  through  the  surrounding  ether  is  capable  of  com- 
municating to  the  photosphere  of  the  sun  exactly  the 
same  quantity  of  motion  in  the  form  of  heat;  and  a 
given  quantity  of  heat  at  present  existing  in  the  photo- 
sphere of  the  sun  is  exactly  equal  to  and  capable  of 
changing  the  same  quantity  of  specialized  vibrations 
into  an  equal  amount  of  unspecialized  or  heat  vibra- 
tions. Action  and  reaction  are  always  equal.  The 
action  of  the  grand  total  of  the  specialized  ethereal 
vibrations  that  fall  upon  the  sun  is  equal  to  and  pro- 


*  We  find  it  very  convenient,  though  perhaps  inaccurate,  to  use  the  phrase — 
"cold  vibrations'1— as  ether  has  no  sensible  heat.  It  is  only  used  in  distinc- 
tion from  thermal  or  heat-bearing  waves. 


56  SOLAR    HEAT. 

duces,  without  loss  or  gain,  the  grand  total  of  the 
unspecialized  ethereal  vibrations  that  leave  the  sun. 
Now  for  the  demonstration.  It  is  as  short  as  the  boy's 
axiom:  "Whatever  goes  up  must  come  down."  The 
sun  radiates  daily  and  hourly  an  inconceivable  amount 
of  heat.  It  is  hung  up  in  space  with  absolutely  no 
means  of  communication  with  the  outside  realms  of 
nature,  except  the  all-enveloping  ether.  This  ether  is 
exactly  adapted  to  the  transmission  of  vibrations  in 
opposite  and  in  all  directions.  These  vibrations  can 
only  be  transmitted  from  ordinary  matter  to  ordinary 
matter,  or  from  suns  and  other  celestial  bodies  to  other 
suns  and  celestial  bodies,  for  there  is  no  other  ordinary 
matter  in  existence.  Ether  itself  can  originate  no  vibra- 
tions. There  is,  therefore,  no  possible  source  for  the 
vibrations  that  supply  the  sun's  heat,  except  other  suns 
and  celestial  bodies,  and  no  possible  mode  of  receiving 
these  vibrations  except  through  the  common  ether.  I 
know  of  but  one  objection,  viz.:  The  incoming  and  out- 
going vibrations  are  widely  different,  as  examined  and 
tested  at  the  way-station  of  earth.  This  objection,  how- 
ever, disappears  when  we  remember  that  all  forms  of 
energy  are  interconvertible. 

It  is  a  very  common  opinion  that  the  ether  immedi- 
ately surrounding  the  sun  is  dense,  if  we  may  use  the 
term,  with  the  rays  of  light  and  heat  leaving  that  lumi- 
nary, but  that  this  heat  diminishes  rapidly,  and  at  great 
distances  from  the  sun  is  replaced  by  intense  cold. 

Now,  if  the  theory  here  advocated  is  true,  then  every 
cubic  inch  of  ether,  wherever  located,  is  as  rich  in  the 
elements  of  heat  as  that  which  lies  in  contact  with  the 
sun.  The  ether  in  contact  with  the  sun  supplies  him 
with  all  his  heat,  and  anv  other  bodv  of  ether  would 


ILLUSTRATIONS    AND    ARGUMENTS.  57 

do  it  just  as  effectually.  If  the  sun  were  lifted  from 
his  seat  and  placed  half  a  million  miles  away,  he  would 
be  just  as  bountifully  supplied  with  heat  as  at  present ; 
in  fact,  he  is  supposed  to  move  through  space  at  about 
this  rate  per  day. 

There  can  be  little  doubt  that  the  earth  and  proba- 
bly all  the  planets,  the  sun  himself,  and  all  other  suns, 
have  in  ages  past  existed  at  a  vastly  higher  temperature 
than  they  possess  at  present.  But  if  all  the  solar  bod- 
ies, even  at  their  present  condition  of  intense  heat,  have 
been  from  a  period  dating  back  into  the  eternities, 
pouring  this  form  of  energy  into  the  space-wide  ether, 
this  ether  must  long  ago  have  become  filled  with  heat 
vibrations  up  to  the  old  nebular  standard,  if  it  has  all 
been  conserved,  unless  changed  to  other  forms  or  com- 
municated to  other  matter.  Both  are  facts.  We  know 
from  experience  that  we  are  not  living  and  breathing 
in  an  atmosphere  of  flame,  consequently  the  fiery  ema- 
nations of  our  sun  and  other  suns  must  be  metamor- 
phosed. But  granting  the  metamorphosis,  the  quantity 
is  not  diminished. 

A  cubic  mile  of  heat,  if  transformed,  would  still  be 
a-  cubic  mile  of  some  other  form  of  energy,  or  at  least 
would  be  capable,  under  the  proper  conditions,  of 
retransformation  into  a  cubic  mile  of  heat. 

But  metamorphosis  alone  would  afford  no  relief. 
Energy,  whether  In  the  form  of  heat  or  any  other  form, 
would  continue  to  accumulate  in  the  ether  (being  all 
conserved),  if  the  suns,  through  all  the  eternities,  con- 
tinued to  pour  this  energy  into  the  ether  and  never 
received  any  in  return. 

Consequently,  the  suns  must  receive  back  as  much  as 
they  send  out.  And,  therefore,  the  whole  universal 


58  SOLAR    HEAT. 

ether  is  absolutely  as  highly  charged  with  energy  capa- 
ble, under  proper  conditions,  of  changing  to  heat  at 
every  point  in  space,  as  when  laden  with  the  whole 
volume  of  heat  leaving  the  sun. 

This  also  follows  from  the  high  degree  of  elasticity 
of  the  ether  and  its  perfect  freedom  to  press  in  all 
directions,  necessitating  absolute  equilibrium  of  motion 
throughout  its  whole  extent. 


CHAPTER   VIII. 

WHY  HAS  THE  EARTH  COOLED  OFF  AND  NOT  THE  SUN  ? 

In  wisdom  God  hath  made  the  world. 
And  still  upholds  its  wondrous  frame ; 
The  planets,  in  their  orbits  whirled, 
Roll  round  their  endless  path  the  same. 

— PERCIVAL. 

THE  eartli  is  now  very  much  cooler  than  the  sun. 
Still,  to  the  practised  eye  of  the  geologist,  it  dis- 
closes the  fact  beyond  all  question  that  it  has,  probably 
in  remote  ages,  existed  at  an  exceedingly  high  tempera- 
ture. Rocks  that  now  come  to  the  surface  show  unmis- 
takable evidence  of  having  existed  in  a  liquid  state. 
Even  now  the  interior  is  fully  believed  by  many  intelli- 
gent persons  to  be  a  vast  globe  of  molten  earths  and 
metals,  covered  by  a  thin  crust  of  indurated  rocks, 
overlaid  with  a  veneering  of  sediment  and  drift.  It  is 
quite  a  general  opinion  among  the  most  judicious  and 
conservative  scholars,  that  the  earth  and  other  planets 
have  at  some  remote  past  time  formed  parts  of  the  sun's 
mass,  and  have,  by  some  process  of  nature,  been 
detached  and  swung  into  their  present  orbits.  If  so, 
these  planets  must  have  commenced  their  separate  exis- 
tence with  the  temperature  of  the  sun  at  the  time  of 
their  separation. 

The  earth  still  shows  us  the  scars  and  scoriae  of 
those  dies  irce.  But,  through  what  lapse  of  ages  we 
cannot  say,  this  earth  has  certainly  been  immensely 

59 


60  SOLAR    HEAT. 

cooled,  either  by  the  transference  of  a  large  portion  of 
its  heat  to  other  regions,  or  by  the  transformation  of  it 
into  other  forms  of  energy.  We  shall,  by  all  means, 
prefer  the  latter  alternative.  With  such  a  leveller  and 
equilibrator  as  the  ether  enveloping  every  denizen  of 
space,  we  cannot  suppose  any  body,  wherever  located, 
to  remain  for  a  moment  emptied  of  its  equal  share  of 
that  energy,  which  is  the  common  inheritance  of  all, 
and  which  is  everywhere  seeking  equal  diffusion.  Much 
less  can  we  imagine  any  sun  or  world  to  remain  in  this 
condition  of  emptiness  for  ages.  We  might  as  well 
imagine  a  vacuum  in  mid-air  or  mid-ocean  as  a  vacuum 
of  energy  in  mid-ether.  If  the  heat  of  the  cooling  earth 
were  tendered  to  any  other  body  already  supplied  with 
its  full  quota,  this  other  body  would  be  obliged  to 
decline  the  offer.  Nature  is  impartial  to  all  parts  of  her 
dominions. 

We  may  imagine  a  wealthy  and  munificent  father 
dividing  his  large  estates  among  a  numerous  family 
according  to  their  respective  circumstances  and  desires. 
To  one  he  gives  money,  to  another  stocks  and  bonds,  to 
another  houses  and  lands,  to  another  ships  and  merchan- 
dise, and  to  another  gold  and  silver  mines,  but  to  all  on 
principles  of  equity  and  equality.  So  Nature  distributes 
her  wealth  bountifully  and  impartially  to  all  her  chil- 
dren, but  not  always  in  the  same  form. 

Is  there  any  way,  then,  by  which  the  earth,  com- 
mencing its  separate  career  with  a  temperature  equal  to 
that  of  the  sun,  could  be  cooled  down  to  its  present 
stage,  though  without  actual  loss?  I  think  there  is.  A 
pound  of  lead  in  the  form  of  bird-shot  possesses  many 
times  the  surface  of  another  pound  in  one  ball.  Radi- 
ation of  heat  is  in  proportion  to  surface;  therefore 


WHY  HAS  THE  EARTH  COOLED  OFF  AND  NOT  THE  SUN?  61 

a  pound  of  heated  lead  in  the  form  of  bird-shot  would 
cool  much  more  quickly  than  one  in  the  form  of  a 
single  shot  or  ball.  But  they  stop  or  absorb  vibrations 
only  in  proportion  to  mass,  each  molecule  arresting  one 
unit  of  radiant  energy.  In  this  way  the  earth  and  other 
planets,  on  their  separation  from  the  sun,  are  at  once 
placed  at  a  double  disadvantage,  compared  with  the 
sun,  as  regards  the  reception  and  retention  of  heat. 
Their  surfaces  and  consequent  power  of  radiation  are 
far  greater,  in  proportion  to  mass,  than  in  the  sun.  The 
earth  will  therefore  radiate  faster  and  cool  more  rapidly 
than  the  sun.  It  also  receives  heat  less  readily.  When 
the  material  of  the  earth  was  first  separated  from  the 
sun,  it  possessed  the  same  temperature  and  would  absorb 
heat  at  the  same  rate.  But  so  soon  as  it  had  become 
slightly  cooler  by  increased  radiation,  its  capacity  for 
absorbing  heat  relatively  diminished.  It  is  a  law  of  the 
material  heavens  that  "unto  him  that  hath  shall  be 
given,  and  from  him  that  hath  riot  shall  be  taken  even 
that  which  he  hath."  I  show  in  another  place  that 
intense  heat  is  a  condition  precedent  to  the  reception  of 
intense  heat  from  the  ether.  These  facts  show  why  the 
heat  of  the  earth  is  less  than  that  of  the  sun,  but  they 
are  consistent  with  the  supposition  that  the  earth  may 
possess  a  full  equivalent  in  other  forms  of  energy. 
The  necessary  result  will  be  that  the  planets  wrill 
become,  and  permanently  remain,  much  cooler  than 
the  sun. 

But  this  cooling  process  is  not  an  endless  one.  An 
equilibrium  has  been  reached,  we  know  not  how  long 
ago,  and  the  earth  now  receives  and  radiates  exactly  the 
same  amount  on  an  average  from  year  to  year.  If  she 
were  receiving  less  than  she  radiates,  she  would  be 


62  SOLAR    HEAT. 

growing  colder;  if  more,  she  would  be  growing  hotter. 
But  neither  is  now  the  ease. 

Equilibrium  of  energy,  however,  is  far  from  being 
equality  as  regards  heat.  The  earth  and  planets  may 
be  richly  endowed  in  forms  of  energy  in  which  the  sun 
is  deficient.  On  this  theory  all  celestial  bodies  will  be 
heated  in  proportion  to  their  respective  masses,  except 
in  so  far  as  their  heat  may  be  influenced  by  proximity 
to  other  heated  bodies  or  suns.  Hence  the  earth  is 
comparatively  cold  and  the  moon  still  colder. 

Venus,  being  nearly  of  the  same  mass  as  the  earth,  is 
believed  to  be  of  about  the  same  temperature.  Mars, 
being  much  less,  is  colder,  his  circumpolar  snow  and 
ice  being  distinctly  visible  at  all  seasons,  while  Jupiter, 
of  almost  solar  dimensions,  is  still  a  red-hot  mass,  his 
fiery  radiance  penetrating  through  the  deep  layers  of 
clouds  by  which  he  is  at  all  times  enveloped. 

The  result  to  our  earth  would  be  just  what  we  find : 
a  world  once  heated  to  fiery  intensity,  but  through  long 
ages  cooled  down  to  a  point  adapted  to  be  the  abode  of 
animals  and  plants.  There  is  every  reason  to  believe 
the  earth  has  reached  just  the  temperature  which  its 
relative  mass  and  position  in  regard  to  the  sun  necessi- 
tate, and  which  adapts  it  to  just  the  purposes  for  which 
the  Creator  designed  it. 

The  sun,  at  the  time  of  his  partial  dismemberment 
to  inaugurate  the  planetary  system,  was,  of  course,  of 
the  same  temperature  as  the  new-born  planets,  but  pos- 
sessed a  comparatively  small  amount  of  radiating  sur- 
face relatively  to  his  mass.  How  much  he  may  have 
cooled  since  this  cataclysmic  rending  of  his  mass,  or,  in 
other  words,  how  much  of  his  energy  of  heat  may  have 
been  metamorphosed  into  energy  of  other  names,  we 


PERPETUATION  OF  SOLAR  HEAT.  63 

cannot  tell.  But  he  also  seems  now  to  have  attained  a 
condition  of  permanency,  becoming  neither  hotter  nor 
colder.  Ills  receipts  appear  to  be  exactly  equal  to  his 
disbursements;  and,  if  heat  be  the  coin  of  his  com- 
merce with  brother  suns,  his  cash  book  will  always 
balance. 

PERPETUATION  OF  SOLAR  HEAT. 

We  have  endeavored  to  show  how  the  earth  and  sun 
have  parted  company  in  regard  to  conditions  of  heat  as 
well  as  relative  position  in  space.  We  will  now  en- 
deavor to  show  by  what  means  this  difference,  when  it 
has  readied  its  full  development,  is  maintained  as  a  per- 
manent arrangement  in  nature. 

The  waves  which  supply  the  solar  fires  do  not  turn  to 
heat  on  encountering  the  earth  : 

First,  because  they  are  in  part  at  least  continued 
unchanged  in  the  form  of  gravitation. 

Second,  because  much  of  the  residue  is  reflected,  as 
light  and  heat  are  from  the  earth  and  moon,  and  so  con- 
tinue their  progress  in  new  directions.  But, 

Thirdly  and  mainly,  because  this  grandest  transfor- 
mation in  nature  requires  for  its  accomplishment  a  lab- 
oratory of  almost  infinite  resources,  self-sustaining  and 
self-perpetuating.  Such  a  laboratory  the  earth  cer- 
tainly does  not  possess.  In  the  economy  of  nature  the 
earth  was  designed  to  be  a  receiver  and  the  sun  a  prox- 
imate producer  of  light  and  heat.  The  sun  is  mascu- 
line and  the  earth  feminine  in  nature  as  well  as  in  name. 

In  all  these  respects  the  sun  is  the  exact  opposite  of 
the  earth.  At  the  sun  the  waves  of  force  cannot  con- 
tinue unchanged  in  the  form  of  gravitation,  because  the 
sun  does  not  change  his  path  as  does  the  earth  in  re- 


64  SOLAR    HEAT, 

v 

spouse  to  their  impact,  but  so  far  as  this  force  is  con- 
cerned remains  nearly  stationary.  Neither  does  the  sur- 
face of  the  sun,  being  composed,  as  I  believe,  of  incan- 
descent carbon  clouds,  reflect  these  waves  unchanged  in 
form.  The  peculiar  nature  of  carbon  in  this  condition 
adapts  it  to  receive  the  cold  vibrations  of  energy  through 
the  ether,  and  return  or  radiate  the  same  transformed 
into  vibrations  of  light  and  heat.  The  vibrations  bearing 
the  name  of  electricity  pass  coldly  along  the  wires  till 
they  meet  a  fine  tibre  or  point  of  carbon  and  then  turn 
to  the  most  dazzling  light  and  heat. 

The  photosphere  I  believe  to  be  composed  of  carbon 
divided  into  the  finest  possible  points,  perhaps  into  ulti- 
mate particles.  These  atoms,  already  heated  to  the  high- 
est incandescence,  like  the  glowing  particles  of  carbon  in 
the  electric  lamp,  receive  the  vibrations  of  ether,  which, 
like  the  vibrations  of  electricity,  if  they  be  not  elec- 
trical themselves,  perpetuate  the  very  h'res  on  which 
they  feed. 

If  the  ethereal  waves  inundant  on  the  sun  can  be 
likened  to  celestial  visitants,  which  they  are  in  fact,  they 
love  a  warm  reception  and  contribute  to  its  warmth. 
It  is  not  impossible  that  these  waves,  whose  existence  no 
one  will  question,  are  as  highly  charged  with  what  Ave 
call  electricity  as  with  mechanical  force ;  and  that,  pre- 
cipitating themselves  upon  the  myriad  carbon  points  of 
the  photosphere,  they  turn  to  light  and  heat  almost 
exactly  as  electricity  does  in  the  electric  lamp ;  that  is, 
by  the  excitation  of  and  resistance  to  electric  currents. 
I  should  lay  more  stress  upon  this  mode  of  transforma- 
tion of  energy,  were  it  not  that  every  dabbler  in  science 
invokes  the  aid  of  electricity  to  solve  every  mystery. 
Still,  the  abuse  of  one  of  the  great  energies  of  nature, 


PERPETUATION  OF  SOLAR  HEAT.  65 

should  not  deter  us  from  assigning  to  it  its  proper  place 
in  the  grand  economy  of  the  universe. 

The  subject  belongs  to  the  electricians,  but  there  are 
some  aspects  of  the  case  open  to  the  ordinary  layman. 

1.  The  only  forms  of  light  and  heat  known  on  earth 
that  bear  any  comparison  with  those  of  the  sun,  are 
produced  by  the  vibrations  of  fine  particles  of  carbon  in 
the  electric  arc  or  lamp,  under  the  influence  of  elec- 
tricity. 

2.  Though  a  well  compacted  carbon  rod,  of  say  half 
an  inch  in  diameter,  is  a  fairly  good  conductor  of  elec- 
tricity, which  will  pass  over  it  without  generating  much 
if  any  heat,  yet,  if  it  be  separated  into  two  pointed  pen- 
cils, intense  light  and  heat  are  the  result.     In  this  case 
light  and  heat  are  proximately  produced  by  the  vibra- 
tion of  carbon  particles  at  the  point  of  contact  or  quasi 
contact  of  the  positive  and  negative  ends  of  the  pen- 
cils.    In  the  incandescent  lamp  the  same  effect  is  pro- 
duced by  a  fine  fibre  or  thread  of  carbon  vibrating  in  a 
vacuum. 

3.  These  vibrations  attack  and  set  in  motion  the  par- 
ticles of  carbon  much  more  readily  when  the  latter  are 
highly  heated  than  when  cold. 

4.  The  electrical  vibrations  arouse  and  shake  the  par- 
ticles of  carbon  most  violently,  when  the  latter  are  not 
only  highly  heated  but  separated  from  each  other  by 
minute  distances. 

Apply  the  above  to  the  incandescent  carbon  clouds  of 
the  photosphere,  if  I  am  correct  as  to  the  constitution  of 
the  latter.  On  this  supposition  these  particles  are  most 
highly  heated,  and,  therefore,  invite  the  attack  of  elec- 
tric waves.  These  particles  are  divided  to  the  last  de- 
gree of  minuteness,  and  thereby  offer  another  induce- 


66  SOLAR    HEAT. 

inent  to  the  action  of  electricity ;  and,  lastly,  while  the 
particles  of  carbon  are  most  finely  divided,  they  are 
near  enough  together  to  be  easily  within  the  range  of 
electrical  action.  These  are  just  the  conditions  that 
electricity  requires  in  order  to  light  and  warm  the  uni- 
verse by  means  of  that  black  demon,  carbon,  transfig- 
ured into  an  angel  of  light.  Here,  then,  we  have  the 
laboratory  where  light  and  heat  are  evolved  from  the 
cold  waves  of  ether,  or,  to  vary  the  figure,  the  furnace 
in  which  the  darts  of  Apollo  are  forged,  compared  to 
which  the  bolts  of  Jupiter  are  fulmina  bruta.  In  this 
furnace, 

*  What 'anvils  rang,  what  hammers  beat, 
In  what  a  forge  and  what  a  heat !  "  * 

The  sun  is  beyond  doubt  the  great  centre  of  energy 
in  our  system.  It  would  be  very  singular,  if  not  incred- 
ible, if  so  pronounced  and  familiar  a  form  of  energy  as 
that  known  by  the  name  of  electricity,  so  readily  changed 
to  heat,  and  vice  versa,  should  be  a  total  stranger  in  the 
sun.  In  fact,  it  is  well  known  that  the  sun,  even  at  the 
distance  of  the  earth,  excites  magnetic  disturbances; 
but  magnetism  and  electricity  are  modified  forms  each 
of  the  other.  We  are  surrounded  by  mysteries,  but  it 
is  unphilosophical  to  involve  again  in  mystery  any  facts 
that  have  been  wrested  from  her  domain  and  added  to 
the  categories  of  knowledge.  It  is  now  well  known 
that  a  current  of  electricity  discharged  along  or  through 
finely  divided  carbon  particles  will,  by  the  processes  of 
induction  and  conduction,  excite  a  vibration  among 
these  particles  that  reveals  itself  by  the  most  intense 
light  and  heat.  That  the  sun's  photosphere  is  composed 
of  finely  divided  incandescent  carbon  clouds,  I  shall 

*  Longfellow. 


PERPETUATION    OF    SOLAR    HEAT.  67 

endeavor  hereafter  to  show  is  highly  probable.  This 
conceded  provisionally,  many  will,  with  the  writer,  be 
strongly  inclined  to  suspect  that  solar  light  and  heat  are 
transformations  of  cosmic  energy  by  means  of  electricity 
and  carbon  particles,  analogous  to  what  we  see  on  a 
minute  scale  in  the  electric  lamp. 

All  that  I  have  ventured,  however,  in  regard  to  the 
agency  of  electricity  in  the  production  of  solar  heat  will, 
for  the  present,  be  received  simply  as  hypothesis.  If 
it  possesses  any  element  of  probability,  others  will  help 
to  advance  the  hypothesis  to  the  higher  rank  of  knowl- 
edge. But  the  grand  fact  that  the  heavens  are  sur- 
charged with  energy  throughout  all  their  boundless 
expanse  of  ether,  ready  at  every  point  to  impart  to  suns 
and  worlds  just  the  forms  and  kinds  which  their  well- 
being  requires,  is  to  my  mind  certain  beyond  a  doubt. 
There  is  also  a  power  of  "  natural  selection,"  not  born 
of  accident,  but  planned  by  infinite,  adaptive  wisdom, 
by  means  of  which  every  sun  and  every  world  draws 
from  this  common  source  the  full  supply  of  all  its  wants. 


OHAPTEK  IX. 

NEBULAR  HYPOTHESIS. 

Erst,  space  was  nebulous. 
It  whirled,  and  in  the  whirl  the  nebulous  milk 
Broke  into  rifts  and  curdled  into  orbs — 
Whirled  and  still  curdled,  till  the  azure  rifts 
Severed  and  shored  vast  systems,  all  of  orbs. 

—  MASSON.     (From  ' « World  Life, "  by  Winchell. ) 

SUCH  was  the  name  which  La  Place  modestly  applied 
to  what  is  now  boldly  denominated  the  nebular  doc- 
trine, resting  on  such  authorities  as  Kant,  La  Place  and 
Sir  William  Herschel,  in  the  last  generation,  and  emi- 
nent scholars  too  numerous  to  name,  in  the  present. 

My  object  is  not  to  rearrange  and  restate  the  learn- 
ing on  this  subject,  but  to  advance  a  few  suggestions 
looking  to  a  more  complete  connection  and  harmony  of 
the  energies  now  in  operation  in  nature. 

"What  are  popularly  known  as  nebulae  are  distin- 
guished into  resolvable  and  irresolvable.  The  former 
are  not  strictly  nebulae  at  all,  but  simply  star  clusters, 
many  of  which  can  be  separated  by  the  aid  of  powerful 
telescopes,  and  those  which  are  too  far  sunken  in  the 
depths  of  space  to  be  resolved  by  even  the  most  power- 
ful glasses,  still  have  their  true  character  indicated  by 
that  most  wonderful  modern  instrument,  the  spectro- 
scope. By  means  of  this  instrument  every  sun,  planet, 
satellite,  nebula  and  comet  is  compelled,  literally,  to 
photograph  itself,  and  not  only  tell  us  the  elements 

68 


NEBULAR    HYPOTHESIS.  69 

of  which  it  is  composed,  but  to  inform  us  of  its  physical 
condition.  These  so-called  resolvable  nebulae  are  shown 
by  this  instrument  to  be  aggregations  of  suns  similar  to 
ours.  But  the  irresolvable  or  real  nebulae  are  shown 
to  be  composed  of  incandescent  gases  only,  or  nebulous 
matter. 

All  who  may  read  this  will  know  from  other  sources 
that  the  spectra  exhibited  by  this  instrument  are  divided 
into  three  distinct  classes : 

1.  The  continuous  spectrum,  which  is  that  of  the 
rainbow,  composed  of  the  seven  primary  colors,  which 
is  given  out  only  by  incandescent  solid  or  liquid  matter, 
either  radiated  or  reflected,  such  as  the  light  of  the  sun, 
planets,  satellites,  and  all  incandescent  solids  and  liquids. 

2.  The  discontinuous  or  bright-lined  spectrum  given 
out  only  by  incandescent  gases  or  vapors,  seen  in  the 
real  nebulae,  in  the  sun's  prominences,  and  in  substances 
volatilized  in  the  electric  arc. 

3.  The  absorption,  dark-lined  or  reversed  spectrum, 
where  the  white  light  of  incandescent  solids  and  liquids 
is  made  to  pass  through  a  medium  of  cooler  gas.    In  this 
case  dark  lines  of  absorption  appear  exactly  where  the 
bright  lines  from  the  same  gas  or  gases  would  appear 
were  they  posing  alone  for  their  photographs. 

As  intimated,  by  this  instrument  the  true  nebulae 
exhibit  only  the  bright-lined  spectra,  which  are  the 
infallible  evidence  of  the  incandescent  gaseous  state  of 
matter.  Although  these  true  nebulae  are  located,  counted 
and  catalogued  by  the  thousand  by  astronomers  who 
devote  their  lives  to  the  study  of  the  heavens,  still  they 
constitute  the  merest  fragments  of  what  is  demanded 
for  the  once  existent  nebular  system.  At  one  stage  of 
cosmic  development,  or  rather  at  its  commencement,  it 


70  SOLAR    HEAT. 

is  believed  that  universal  space  was  filled  with  the 
matter,  in  the  form  of  incandescent  gases,  which  now 
compose  the  suns,  worlds,  and  other  celestial  bodies  that 
people  immensity.  This  is  believed  to  have  constituted 
the  Taw  material  from  which  suns  and  worlds  have 
been  evolved. 

It  is  customary  with  many  writers,  in  endeavoring  to 
outline  the  history  of  the  changes  which  this  raw,  or 
rather  overdone,  material  has  undergone,  to  begin  with 
a  slight  cooling  oif,  ?,nd  proceed  from  one  stage  of  cool- 
ing to  another,  until  the  nebulous  matter,  which  in  our 
system  filled  all  space  far  beyond  the  orbit  of  Neptune, 
has  shrunk  to  the  mere  points  in  comparison  repre- 
sented by  the  bodies  of  our  solar  system. 

But  whither  has  this  incalculable  amount  of  heat 
gone?  It  would  be  idle  to  say  it  had  invaded  other 
systems,  for  they  are  cooling  off  simultaneously,  and 
have  as  much  surplus  heat  to  dispose  of  as  our  system. 

This  subject  does  not  seem  to  have  troubled  much 
the  writers  on  physics.  It  seems  to  have  been  consid- 
ered sufficient  in  a  general  way  to  say  that  the  nebulous 
mass  has  gradually  "  cooled  down,"  but  where  the  heat 
given  off  has  gone,  they  do  not  even  conjecture.  In 
fact,  they  do  not  tell  us  that  it  has  gone  anywhere,  but 
seem  to  intimate,  if  they  do  not  assert,  that  it  has  gone 
out  of  existence.  If  this  is  so,  what  becomes  of  the 
doctrine  of  "  conservation  of  energy  "  ? 

Heat  is  now  measured  by  cubic  miles,  and  a  cubic 
mile  of  heat  can  no  more  be  annihilated  than  a  cubic 
mile  of  lead  or  iron. 

Let  us  imagine,  for  a  moment,  all  space  to  have  been 
filled  with  solid  matter,  as  dense  as  our  earth,  instead 
of  gaseous  matter  expanded  almost  to  the  tenuity  of 


NEBULAE    HYPOTHESIS.  71 

ether  by  intensest  heat.  We  know  that  at  the  pres- 
ent time  space  is  very  sparsely  sprinkled  with  celestial 
bodies,  large  when  separately  considered,  and  many  of 
them  immense,  but  mere  points  in  comparison  with  the 
intervening  spaces.  Would  it  be  a  sufficient  explana- 
tion of  the  present  absence  of  matter  in  the  interstellar 
spaces  to  say  that  the  matter  which  once  filled  all  space 
solid  had  become  highly  heated,  vaporized,  driven  off 
and  lost?  The  question  would  be  asked,  Where  could 
it  go,  if  all  space  was  already  packed  solid  with  similar 
matter  ? 

Now  heat  is  not  matter,  but  it  is  energy  as  indestruct- 
ible as  matter.  While  this  nebulous  state  of  matter  ex- 
isted, heat  was  undoubtedly  the  agent  by  means  of  which 
the  matter  of  the  universe  was  then  expanded  to  its  ex- 
tremest  volume  and  tenuity.  Consequently  the  heat  of 
the  whole  realms  of  space  occupied  by  this  tenuous  form 
of  matter  was  then  at  its  utmost  maximum  of  intensity 
and  co-extensive  in  this  form  with  space,  a  very  differ- 
ent state  of  things,  surely,  from  the  present. 

This  volume  of  heat  —  for  we  are  now  allowed  to 
measure  it  by  cubic  miles — cannot  be  gotten  rid  of  by 
saying  it  is  radiated  into  space  and  lost,  for  all  space  is 
supposed  to  be  surcharged  with  the  same  form  of 
energy.  It  cannot  be  annihilated  on  the  spot,  at  the 
very  horns  of  its  own  altars,  for  that  would  involve  the 
explosion  of  the  grandest  discovery  of  modern  times  — 
the  conservation  of  energy.  What,  then,  has  become  of 
this  heat?  If  the  principles  I  have  applied  to  solar 
heat  are  true,  they  will  solve  this  problem  with  equal 
ease. 

Let  us  then  approach  this  question  by  the  light  of 
these  principles. 


2  SOLAR    HEAT. 

In  the  nebulous  condition,  matter  is  literally  in  its 
nascent  state,  in  the  very  condition  in  which  it  had  its 
birth.  The  sum  total  of  its  energy  is  expressed  in  one 
word  —  heat. 

Mechanical  motion,  gravitation,  attraction  of  "cohe- 
sion, chemical  affinity,  electricity,  magnetism,  and  the 
forces  of  life,  or  vires  vivce,  are  all  for  the  time  merged 
in  heat.  The  undeveloped  capacities  for  the  exercise  of 
these  latter  forms  of  energy  exist  in  matter,  but  their 
action  has  not  yet  commenced.  Every  one  is  familiar 
with  the  fact  that  at  certain  high  temperatures  chemical 
affinity  ceases ;  so  of  cohesion  and  other  forms  of  energy. 
It  is  only  a  truism  to  assert  that  when  all  energy  of 
every  kind  is  concentrated  in  one  form,  viz.,  heat,  then 
all  other  forms  of  energy  are  for  the  time  non-existent, 
or  rather  they  exist  only  wrapped  up  in  the  general  or 
unspecialized  form  of  heat. 

There  existed  then  not  a  breeze  nor  a  ripple  in  all 
this  universal  realm  of  fire,  for  heat  monopolizes  the 
sum  total  of  physical  energies.  Mechanical  motion  has 
not  yet  materialized.  So  of  gravitation,  chemical  affin- 
ity, and  all  the  other  forms  of  energy. 

Pluto,  with  his  naming  sceptre,  reigns  supreme  over 
all  the  realms  of  space.  This  is  the  nebular  condition 
of  matter,  but,  thanks  to  a  beneficent  Creator,  it  is  not 
its  eternal  condition. 

I  said  that  in  the  purely  nebular  condition  of  matter 
there  is  no  mechanical  nor  any  other  form  of  motion 
except  heat.  But  heat  itself  is  motion  of  a  general 
kind  as  truly  as  any  other  form  of  energy,  and  the  more 
intense  the  heat,  the  more  rapid  the  molecular  vibra- 
tions. Every  particle  of  matter  under  its  influence  is 
like  a  champing  steed,  impatient  to  be  in  motion,  but 


NEBULAR    HYPOTHESIS.  73 

hemmed  in  on  every  side.  But  this  condition  was  not 
intended  to  be  permanent,  though  through  what  ages  it 
may  have  existed,  we  cannot  tell. 

Without  attempting  to  penetrate  these  awful  myste- 
ries to  their  inmost  recesses,  we  may  safely  say  that  one 
of  the  first  specializations  of  energy  from  the  all-embrac- 
ing form  of  heat  was  mechanical  motion  in  the  form 
of  immense  vortices.  I  know  I  am  using  a  much-abused 
term,  but  I  have  the  highest  authority  for  its  use  in  this 
connection.  This  vortical  motion  is  still  swinging  the 
planets  in  their  orbits,  and  rotating  them  and  the  sun 
on  their  axes. 

But  this  new  form  of  energy,  as  already  intimated,  is 
not  newly  created,  but  drawn  from  the  great  storehouse 
of  energy,  already  existing  in  the  form  of  heat.  Now, 
we  have  the  nebular  heat  very  materially  diminished 
and  the  nebular  matter  correspondingly  cooled,  a  por- 
tion of  the  heat  having  been  transformed  into  mechani- 
cal motion.  The  particles  are  now  brought  more  nearly 
together,  and  the  mass  composing  our  solar  system 
is  shrunk  to  much  smaller  dimensions.  The  same 
process  going  on  simultaneously  in  the  vortices  compos- 
ing other  incipient  systems,  large  spaces  of  open  sky 
will  appear  free  from  all  forms  of  matter  except  the 
universal  ether  and  permanent  gases. 

This  cooling  of  the  particles  and  agitation  by  vortical 
motion  will  cause  the  clashing  and  coalescing  of  homo- 
geneous particles ;  and  another  new  form  of  energy, 
that  of  cohesion,  to  the  extent  peculiar  to  liquids,  is 
born.  But  this  new  force  makes  another  draft  upon 
the  common  stock  of  heat,  accompanied  by  another 
contraction.  So  gravitation,  chemical  attraction,  elec- 
tricity, magnetism,  and  imally  vis  viva,  each  in  its 


74  SOLAR    HEAT. 

proper  order,  will  appear,  assert  its  rights  and  draw 
from  the  common  stock  the  proper  amount  of  cosmic 
energy,  accompanied,  of  course,  by  cooling  and  con- 
traction of  the  matter  of  our  system  until  the  present 
equilibrium  is  attained.  In  all  these  processes  heat  is 
neither  destroyed  nor  lost,  but  differentiated  into  the 
various  forms  of  energy  necessary  to  the  harmonious 
action  of  all  parts  of  the  system. 

I  need  not  go  farther  into  the  details  of  the  steps  in 
the  progress  of  matter  from  nebulae  into  suns,  planets 
and  satellites,  by  means  of  transformations  of  energy, 
contraction,  simulation  and  the  action  of  centripetal, 
centrifugal  and  rotary  forces.  This  has  been  done  far 
more  fully  than  I  have  space  for,  by  Prof.  Alex.  Win- 
chell  and  others. 

Of  course  it  will  be  understood  that  vast  amounts  of 
heat  will  be  radiated  by  the  matter  of  our  system  while 
undergoing  the  changes  indicated,  but  it  will  receive  in 
return  an  equal  amount  in  some  of  the  forms  of  energy 
from  other  metamorphic  systems  undergoing  similar 
changes. 

It  will  also  be  understood  that  at  every  step  in  the 
contraction  of  the  matter  of  our  system,  as  well  as  of 
every  other,  heat  will  be  given  out  by  condensation,  or 
rather  cooling  will  be  retarded,  but  not  to  the  amount 
of  the  demands  of  the  new-born  energies  that  come  into 
exercise  at  each  step  of  cosmic  evolution. 

If  any  one  of  my  readers  finds  himself  unable  to  go 
with  me  the  w^hole  distance  back  to  the  point  in  eter- 
nity, when  Pluto  reigned  without  a  rival  and  heat  con- 
stituted the  totality  of  energy,  he  may  choose  his  own 
starting  point  at  any  stage  which  he  is  pleased  to  con- 
sider the  primeval  condition  of  matter.  I  simply 


NEBULAR    HYPOTHESIS.  75 

accept  the  nebular  hypothesis  cr  doctrine,  as  many 
wiser  men  have  done,  because  I  believe  it  to  represent 
the  order  of  cosmic  evolution. 

My  sole  object  has  been  to  point  out  a  way  in  which 
this  evolution  could  take  place  without  the  loss  of 
heat  or  energy,  and  in  harmony  with  the  doctrine  of 
conservation. 

Another  question  of  surpassing  interest  will  occur  at 
this  point,  viz. :  May  not  this  process  of  evolution  and 
cooling  off  go  on  till  the  earth  and  other  planets,  and 
even  the  sun  himself,  are  so  far  cooled  down  as  to  ren- 
der all  the  planets  uninhabitable  ? 

I  am  no  prophet,  especially  of  evil.  I  know  of  no 
elements  of  danger  except  the  folly  and  wastefulness  of 
man.  There  can  be  no  further  cooling  off  of  the  sun 
or  planets  unless : 

1.  Some  new  form  of  energy  is  about  to  make  its 
appearance,  into  which  the  remaining  heat  or  a  consid- 
erable part  of  it  will  be  converted  ;  or, 

2.  Unless  the  existing  forms  of  energy,  other  than 
heat,  shall  be  largely  augmented  at  the  expense  of  the 
latter. 

In  regard  to  the  first  I  remark :  We  cannot  say 
that  the  creation  of  such  a  new  form  of  energy  from 
older  forms  would  be  an  impossibility,  nor  would  it  be 
beyond  the  power  of  Omnipotence  to  gather  together 
all  the  planetoidal  fragments  revolving  between  the 
orbits  of  Mars  and  Jupiter  into  one  new  planet.  Either 
would  involve  an  exercise  of  creative  power,  and  one  is, 
so  far  as  we  know,  as  improbable  as  the  other. 

In  regard  to  the  second  contingency,  I  know  of  no 
reason  to  suspect  that  gravitation,  or  the  centrifugal 
motion  of  the  earth,  or  electricity,  or  any  other  form  of 


76  SOLAR    HEAT. 

energy  affecting  this  earth,  or  the  system  to  which  it 
belongs,  is  about  to  undergo  an  increase  at  the  expense 
of  the  present  stock  of  heat,  and  thus  destroy  the  pres- 
ent equilibrium. 

Of  all  this  it  may  be  said,  "The  theory  is  very 
beautiful,  but  how  do  we  know  it  is  true  ? "  To  which  I 
reply  by  way  of  brief  recapitulation : 

1.  The  reader,  equally  with  the  writer,  believes  in  the 
pre-existent  nebular  condition  and  universal  diffusion  of 
matter  by  heat.     A  proof  of  this,  not  heretofore  men- 
tioned, but  having  almost  the  force  of  demonstration, 
is  furnished  by  rigorous  mathematical  calculations,  in 
which  it  is  shown  from  the  present  elements  of  the  sun 
that  at  the  times  respectively  when  his  periphery  was 
coterminous  with  the  orbits  of  the  different  planets,  the 
rotary  motion   of   his  surface   corresponded  with   the 
present  motion  of  these  planets  in  the  same  orbits.    This 
fact  has  satisfied    the  most  conservative  scholars,  not 
only  of  the  truth  of  the  pre-existent  nebular  condition 
of  matter,  but  that  the  matter  of  the  different  planets 
was  separated  from  the  sun  by  annulation  at  the  dis- 
tances now  represented  by  the  radii  of  their  respective 
orbits. 

2.  This  nebular  condition  and  diffusion  by  heat  at  the 
commencement  of  the  evolution  of   our  system  being 
conceded,  the  reader  will  further  concede  that  while  the 
whole   field   was   so   completely   occupied    by   cosmic 
energy  in  the  form  of  heat,  there  was  neither  room  nor 
function   for  any   other    form   of    energy.     Chemical 
affinity  could  not  and  did  not  exist ;  the  same  is  true  of 
cohesion,  and  analogy  would  lead  us  to  believe  that  the 
same  was  then  true  of  all  other  forms  of  energy,  heat 
alone  excepted. 


NEBULAR    HYPOTHESIS.  7Y 

3.  Every  intelligent  reader  knows  that  all  forms  of 
energy  are  both  interconvertible  and  indestructible.  It 
is,  therefore,  certain  that  all  other  forms  of  energy,  such 
as  mechanical  motion,  gravitation,  centrifugal  motion, 
rotary  motion,  etc.,  etc.,  must  have  emanated  from  this 
one  common  stock  of  universal  heat,  and  this  common 
stock  must  necessarily  have  been  diminished  in  exact 
proportion  to  the  amount  thus  assuming  other  forms. 
As  heat  is  the  cause  of  expansion,  so  its  absence  is 
necessarily  attended  by  contraction. 

We  have  considered  these  metamorphoses  of  heat  in 
relation  to  our  system  only,  though  some  and  probably 
all  of  these  forms  of  energy  travel  freely  and  swiftly 
through  all  the  realms  of  space  by  means  of  the  all-per- 
vading ether.  But,  as  u  free  trade "  is  the  law  of  the 
heavens,  as  much  is  received  by  each  system  as  it  sends 
abroad,  and  the  result  is  unchanged. 

Therefore,  I  think  we  are  justifiable  in  claiming: 

First,  that  heat  is  the  original  fountain  of  all  forms 
of  energy. 

Second,  that  these  forms  of  energy  pass  through 
endless  transformations  and  transmigrations,  but  never 
invade  the  limbo  of  annihilation. 

Third,  that  the  heat  of  the  sun,  though  widely  dif- 
fused, is  not  lost,  but  flows  into  that  one  illimitable 
ethereal  ocean,  from  which  every  sun,  and  through  the 
suns,  every  world,  receives  its  daily  and  hourly  supply. 

I  am  aware  that  many  scholars  of  the  highest  repu- 
tation, while  holding  to  the  nebular  theory  so  far  as  the 
space-wide  diffusion  of  matter  is  concerned,  hold  also 
that  instead  of  intense  heat,  intense  cold,  perhaps  down 
to  the  absolute  zero  of  temperature,  prevailed  during 
the  nebular  ages.  The  object  of  replacing  the  intense 


78  SOLAR    HEAT. 

heat  of  the  nebular  condition  by  intense 'cold  is  scarcely 
disguised.  It  is  to  afford  an  opportunity  for  contraction 
to  supply  this  same  heat,  at  least  to  the  extent  now  or 
formerly  demanded  by  the  exigencies  of  the  sun.  I 
reply : 

1.  This  is  contrary  to  the  views  of  Kant,  La  Place, 
and  Herschel,  the  authors  of  the  nebular  hypothesis, 
and  all  their  supporters  until  very  recent  times.  This, 
however,  counts  for  very  little,  as  many  discoveries 
have  been  made  since  their  day,  though  I  am  not  aware 
of  the  discovery  of  any  agency  except  heat  by  means 
of  which  matter  can  be  expanded  to  the  gaseous  state. 

2.  The  nebulae  at  present  existing,  which  are  sup- 
posed to  be  the  remnants  of  a  once  universal  nebular 
condition  of  matter,  are  all,  as  shown  by  the  spectro- 
scope, composed  of  incandescent  gases. 

3.  There  is  no  known  agency  by  which  universal 
matter  could  be  held  in  so  divided  and  expanded  a  con- 
dition as  to  fill  all  space,  except  heat  of  the  highest 
conceivable  intensity. 

Just  here  arises  a  most  startling  thought,  which,  at 
first  glance,  and  so  far  as  I  can  see  at  final  glance, 
seems  undeniably  true.  It  is  this:  If  every  motion 
of  every  kind,  except  heat,  in  all  the  bodies  of  the 
solar  system,  including  tangential,  centripetal,  rotary 
and  translatory  motions,  could  at  once  be  arrested,  the 
nebular  condition  would  be  restored,  so  far  as  our  sys- 
tem is  concerned.  If  the  same  could  also  take  place  in 
all  other  systems,  the  universal  nebulous  state  would 
again  prevail.  If  such  a  condition  once  existed  in  the 
remote  past  through  intensest  heat,  and  if  all  the  heat 
then  existing  is  still  extant  in  metamorphosed  forms, 
and  could  be  arrested  and  reconverted  into  heat,  then 


NEBULAR    HYPOTHESIS.  79 

instead  of  the  universal  refrigeration  which  some  emi- 
nent scientists  have  looked  forward  to  with  gloomy 
forebodings,  we  should  have  the  heavens  again  aflame 
with  nebular  fire.  One  catastrophe,  I  opine,  is  as  im- 
probable as  the  other. 


CHAPTER  X. 

WHAT  IS  ENERGY?— POTENTIAL  ENERGY. 

And  there  thy  searching  heat  awoke  the  seeds 

Of  all  that  gives  a  charm  to  earth  and  lends 

An  energy  to  nature.  — PERCIVAL. 

ENERGY  is  the  power  or  capacity  which  one  body 
has  to  perform  work  on  another  body.  The  work 
performed  in  every  case  is  the  communication  of  motion. 
Thus  a  body,  A,  performs  work  on  a  body,  B;  B  repeats 
this  work  on  C,  C  on  D,  and  so  on  until  Z  repeats  the 
same  or  equivalent  work  on  A.  In  other  words,  at  the 
end  of  every  system  of  operations,  however  wide  may  be 
the  circuit,  A  is  restored  to  the  same  condition  in  which 
it  was  found  at  the  commencement  of  the  series.  Each 
body  in  the  series,  in  communicating  its  motion  to 
another,  loses  its  own  motion,  and,  so  far  as  that  partic- 
ular motion  is  concerned,  is  set  at  rest.  It  cannot  com- 
municate its  motion  to  another  body  and  at  the  same 
time  retain  the  same  motion. 

Whence,  then,  comes  the  original  energy  which  set 
the  first  body  in  motion,  or  rather,  which  first  set  the 
whole  machinery  of  the  universe  in  motion  ?  We  can 
only  trace  it  backward  through  an  infinite  series  to  the 
first  cause. 

We  may  then  define  energy  in  the  concrete  as  "  matter 
in  motion,"  set  in  motion  by  other  matter  in  motion, 
and  this  by  still  other  matter  in  motion,  with  no  resting 
place  in  the  past  till  we  arrive  at  creative  power,  which 

80 


POTENTIAL    ENERGY.  81 

created  and  set  in  motion  the  whole  machinery  of 
nature,  and  no  resting  place  in  the  future  this  side  of 
annihilation.  It  matters  not  whether  we  consider  energy 
to  be  strictly  identical  with,  or  strictly  identified  with, 
matter  in  motion.  If  there  be  a  sublimated  something 
which  is  neither  matter  nor  motion,  but  which  always 
accompanies  matter  in  motion  and  causes  that  motion, 
it  is  a  something  of  which  we  know  nothing,  and  of 
which  we  can  affirm  nothing.  It  seems  to  me  more 
rational  to  say  that  matter  is  admirably  and  perfectly 
adapted  to  every  kind  of  motion  required  of  it;  and 
that  motion,  which  could  originally  arise  only  from  a 
creative  impulse,  is,  in  its  nature,  indestructible,  just  as 
matter  is  indestructible,  except  by  the  fiat  of  Omnipo- 
tence. If  motion  is  indestructible,  and  matter  has  been 
wisely  and  perfectly  adapted  to  receive,  conserve  and 
transmit  all  possible  kinds  of  motion,  representing  all 
the  forms  of  what  we  call  energy,  we  cannot  see  any 
need  nor  any  room  for  any  other  force  or  energy  in 
nature.  This  affirms  or  denies  nothing  in  regard  to  God 
in  nature.  The  latter  subject  belongs  to  the  domain  of 
theology,  and  not  to  philosophy.  But  the  demand  for  a 
God  in  nature,  in  the  sense  of  a  present  acting  cause  of 
all  natural  phenomena,  seems  to  me  to  be  the  very 
essence  of  pantheism.  Philosophy  would  then  have  no 
foundation,  for,  if  all  natural  phenomena  rest  on  arbi- 
trary will,  the  phenomena  of  to-day  may  be  reversed 
to-morrow. 

POTENTIAL  ENERGY. 

It  may  seem  aside  from  my  main  purpose,  which  is 
to  account  for  solar  heat  and  gravitation,  and  show  the 
relation  between  them,  to  discuss  the  subject  of  poten- 
6 


82  SOLAR    HEAT. 

tial  energy.  But  if  it  is  possible  for  potential  energy, 
no  one  knows  to  what  extent,  to  be  stored  up,  no  one 
knows  where,  and  capable  of  being  developed  whenever 
wanted  to  an  unknown  amount,  then  it  is  unnecessary 
to  trouble  ourselves  to  discover  any  source  for  the  heat 
of  the  sun.  All  we  have  to  do  is  to  suppose  that  a 
sufficient  amount  of  potential  energy  will  from  time  to 
time  become  kinetic,  to  answer  all  the  requirements  of 
the  sun,  and  if  the  supply  should  ever  fail,  it  will  only 
be  after  the  lapse  of  such  "absolutely  incalculable 
future  ages,"  *  that  it  is  of  no  practical  interest  to  us. 
This  doctrine  of  potential  energy  may  not  affect  us  as 
individuals,  but  it  concerns  vitally  a  true  theory  of  solar 
heat. 

We  do  not  aspire  to  the  honors  of  an  iconoclast,  and 
he  would  be  a  very  bold  man  who  should  apodictically 
pronounce  potential  energy  to  be  a  myth,  after  all  the 
learning  and  research  that  have  been  expended  on  the 
subject,  and  all  the  mathematical  formulae  in  which  it 
has  been  dressed.  Yet,  if  one  does  not  believe  in  its. 
existence,  what  can  he  honestly  do  but  to  say  so? 
Besides,  if  I  do  not  say  so,  somebody  else  will,  for  the 
truth  will  out,  if  truth  it  be.f  If,  on  the  contrary,  the 
bare  suggestion  of  the  non-existence  of  potential  energy 
is  a  flat  absurdity,  I  am  not  the  first  and  will  not  be  the 
last  writer  of  absurdities.  So,  with  all  the  respect  I 
entertain  for  men  of  greater  learning,  I  invite  the  atten- 
tion of  the  reader  to  a  few  reasons  for  disbelieving  in 
the  existence  of  potential  energy,  if  I  understand  the 
term.  I  think  I  am  stating  the  position  of  the  advo- 

*  Stewart  and  Tait's  "Unseen  Universe,"  page  127. 

t This  was  written  before  my  eye  fell  upon  Stallo's  "Modern  Physics," 
page  29,  where  he  says:  "All  potential  energy,  so-called,  is,  in  reality,  kinetic." 


POTENTIAL   ENERGY.  83 

cates  of  potential  energy  fairly,  as  energy  stored  up  and 
laid  away,  not  acting,  but  ready  to  act  when  the  proper 
circumstances  arise. 

Now,  if  the  very  essence  of  physical  energy  is  matter 
in  motion,  or  if  it  is  indissolubly  united  to  matter  in 
motion,  then  energy,  separate  from  matter  in  motion,  is 
an  impossibility.  Motion  is  never  motionless.  Matter 
in  motion  cannot  at  the  same  time  be  matter  at  rest. 
Motion  may  change  its  form,  its  direction,  its  subject, 
but  on,  on,  on,  it  must  go  forever.  One  body  may 
communicate  its  motion  to  another  body  and  thereby 
come  to  a  state  of  rest,  so  far  as  that  particular  motion 
is  concerned,  or  rather  one  body  may  awaken  in  another 
the  same  kind  of  motion  of  which  it  is  the  subject,  or 
a  related  form,  as  heat  may  awaken  chemical  action,  or 
mechanical  motion  may  awaken  that  form  of  motion 
which  we  call  electricity,  etc.  Motion  in  matter  never 
stops  without  awakening  motion  of  the  same  or  of 
some  other  kind  in  other  matter.  Let  us  now  inquire 
what  becomes  of  the  energy  or  effective  motion  which 
is  said  to  become  potential  or  latent  under  certain  cir- 
cumstances. 

1.  In  melting  ice  at  32°  Fahrenheit  into  water,  also 
at  32°,  143  units  of  heat  are  absorbed  by  the  ice  which 
do  not  appear  as  heat  in  the  water.  And  in  raising 
water  at  212°  to  steam,  also  at  212°,  967  units  of  heat  are 
absorbed  by  the  water  which  do  not  appear  as  heat  in  the 
steam.  The  reverse  of  this  takes  place  when  steam  is 
condensed  to  water  and  water  congealed  into  ice.  But 
this  is  no  longer  regarded  as  heat  becoming  alternately 
latent  and  sensible.  The  heat  apparently  lost  in  melt- 
ing ice  and  vaporizing  water  is  now  regarded  as  doing 
internal  work  on  the  molecules.  But  the  motion  thus 


84  SOLAR    HEAT. 

given  to  the  molecules  in  melting  ice,  for  example,  is 
retained  by  them  until  the  water  is  again  congealed,  as 
that  exact  amount  of  heat  motion  is  given  out  again  in 
freezing.  We  know  to  a  certainty  that  14-3  units  of 
heat,  which  all  agree  is  molecular  motion,  are  commu- 
nicated to  ice  at  32°,  which  do  not  appear  in  the  form 
of  heat  in  the  water.  One  of  two  things  must  be  true, 
either  this  molecular  motion  must  terminate  absolutely 
in  the  melting  ice,  and  is  never  communicated  to  the 
water,  which  would  violate  the  law  of  conservation,  or 
else  the  molecules  of  the  water  do  receive  and  take  on 
a  peculiar  motion  other  than  heat,  which  they  do  not 
possess  in  the  form  of  ice,  and  whicli  they  retain  during 
their  whole  existence  as  water  until  it  is  again  congealed 
into  ice.  "When  so  congealed,  this  motion  of  liquidity 
is  arrested,  and  like  all  arrested  motion  turns  to  heat. 
So  in  water  passing  into  steam.  The  967  units  of  heat 
entering  the  water,  but  not  apparent  in  the  steam  as 
heat,  do  not  cease  to  exist,  but  are  conserved  and  enter 
into  the  steam  as  a  kind  of  motion  peculiar  to  the 
molecules  in  that  condition.  This  motion  it  retains 
until  the  steam  is  again  condensed  into  water,  and  the 
arrested  molecular  motion  peculiar  to  steam  turns  to 
heat  as  in  the  case  of  ice. 

In  both  of  these  cases  there  is  no  dormant  or  poten- 
tial energy.  The  motion  goes  on  perpetually.  It  may 
be  obscured  for  a  time,  like  a  river  flowing  underground, 
but  comes  to  light  as  soon  as  the  steam  is  condensed  to 
water  or  the  water  congealed  to  ice.  This  is  simply 
mechanical  motion,  which,  in  the  case  of  steam,  is  striv- 
ing to  burst  the  boiler. 

2.  But  it  may  be  said :  "  When,  by  means  of  steam 
or  other  power  a  weight  is  lifted  from  the  bottom  to  the 


POTENTIAL    ENERGY.  85 

top  of  a  perpendicular  precipice,  the  energy  employed 
in  raising  the  weight  is  just  equal  to  that  generated  by 
the  weight  in  falling  back,  but  while  the  weight  rests 
upon  the  top  of  the  precipice  the  energy  is  potential." 
We  think  not;  the  weight  exerts  no  more  but  rather 
less  force  by  downward  pressure  in  the  new  position 
than  in  the  old.  It  has  not  gained  to  the  smallest 
degree,  but  rather  lost  in  the  power  of  doing  work.  In 
either  position,  if  the  underpinning  were  removed  the 
weight  would  commence  to  fall,  but  if  the  precipice 
were  a  high  one,  the  weight,  on  a  level  with  the  bot- 
tom, would  begin  its  fall  with  an  appreciable  excess 
of  momentum  over  that  of  the  elevated  weight. 

It  is  true,  that  the  amount  of  gravitative  force  over- 
come by  lifting  the  weight  is  just  equal  to  the  amount 
that  would  be  employed  in  bringing  it  down.  But  that 
amounts  only  to  affirming  the  familiar  truth  that  action 
and  reaction  are  equal.  The  force  employed  in  lifting 
the  weight  against  gravity  has  not  become  potential,  but 
has  taken  a  new  direction  by  reaction  against  the  engine. 

3.  Again  it  may  be  said,  "  The  energy  of  the  sun's 
heat  decomposes  carbon  dioxide  in  the  leaves  of  trees 
and  other  plants,  depositing  the  carbon  and  setting  the 
oxygen  free.  This  carbon  when  burned  in  the  form  of 
coal,  long  ages  afterward,  gives  out  the  same  amount 
of  heat  that  was  expended  in  first  separating  it  from 
the  oxygen.  While  the  coal  lies  in  the  ground  is  not 
this  heat  potential  $ "  This  is  supposed  to  be  unanswer- 
able. But  let  us  see.  The  solar  heat  expended  on  the 
molecules  of  carbon  dioxide,  in  decomposing  them,  was 
communicated  directly  to  these  molecules  and  by  them 
to  others  in  endless  succession,  and  is  still  somewhere  in 
progress. 

6 


86  SOLAR    HEAT. 

But  the  carbon  and  oxygen  together  occupy  a  much 
larger  space  after  decomposition  than  before,  and,  of 
course,  there  is  an  apparent  loss  of  heat  by  rarefaction, 
not  by  becoming  potential.  So  when  the  coal  is  after- 
ward burned,  it  does  not  combine  with  the  identical 
oxygen  nor  give  out  the  identical  heat  by  means  of 
which  the  decomposition  was  effected.  But  the  volume 
of  the  resultant  carbon  dioxide  being  much  less  than 
that  of  the  carbon  and  oxygen  before  their  union,  heat 
will  be  developed  by  condensation,  and  no  potential 
energy  is  involved. 

4.  Perhaps  the  strongest  case  of  so-called  potential 
energy  is  presented  by  an  elastic  spring,  coiled  or  bent, 
and  fastened  in  that  position.  Here  seems  to  be  s  clear 
case  of  energy  locked  up  and  stored  away  ready  for  use 
at  any  future  time.  But  is  it  certain  after  all  that  the 
energy  in  the  spring  has  gone  to  sleep?  The  very 
opposite  seems  absolutely  certain.  The  energy  is 
struggling  every  moment  with  opposing  forces.  The 
opposing  forces  are  the  fastening  that  prevents  its 
uncoiling,  cohesion  in  the  convex  and  compression  in 
the  concave  surface  of  the  spring.  In  coiling  the 
spring  the  force  was  so  applied  as  to  crowd  more  closely 
together  the  molecules  in  the  concave  side,  and  effect  a 
strain  tending  to  pull  apart  the  molecules  in  the  convex 
side  of  the  spring.  This  double  strain  must  last  till 
either  the  spring  is  released  or  breaks  or  loses  its  elas- 
ticity ;  and  until  one  of  these  events  occurs  a  constant 
molecular  activity,  working  toward  one  or  all  of  these 
ends,  is  kept  up.  But  does  this  molecular  motion  per- 
form any  work?  It  matters  not  whether  it  is  doing 
work  or  not.  It  is  sufficient  if  the  motion  itself  sur- 
vives. What  is  meant  by  the  technical  phrase  "  doing 


POTENTIAL    ENERGY.  87 

work"  is  simply  the  transference  of  motion  from  one 
body  to  another ;  the  first  is  cooling  or  losing  motion, 
while  the  second  is  gaining  heat  or  some  other  form  of 
motion;  but  the  spring  is  doing  all  the  work  possible 
under  the  circumstances ;  every  vibration  tends  to  read- 
just the  molecules  so  as  to  make  the  bend  permanent, 
destroy  the  elasticity,  or  break  the  spring.  No  bent 
spring  will  last  forever. 

Nature  is  content  to  work  with  patience  and  in 
obscurity,  as  well  as  with  vehemence  and  brilliancy. 
The  forces  of  nature  are  always  at  work.  They  know 
no  cessation,  no  weariness  and  no  rest.  If  an  atom  in 
motion  could  divest  itself  of  its  motion  without  commu- 
nicating motion  to  another  atom,  and  go  to  sleep,  so 
could  a  world.  If  a  world,  so  could  a  sun.  If  a  sun, 
so  could  the  universe;  and  who  should  awake  them? 
Even  what  we  call  sleep  is  the  season  of  the  greatest 
activity,  when  all  the  organs  of  the  body  are  busy  repair- 
ing the  wastes  of  the  previous  day.  Heat,  with  every 
other  form  of  energy,  is  motion  of  some  kind  or  other. 
To  say  that  the  molecules  of  matter  can  cease  their 
motion  without  communicating  motion  to  other  mole- 
cules, and  .then  resume  their  motion  without  assistance 
from  other  molecules  in  motion,  is  contrary  to  all  sound 
philosophy,  if  not  a  palpable  absurdity.  Matter  in 
motion  cannot  cease  to  move  unless  stopped  by  some 
other  body,  and  in  that  case  the  latter  takes  up  and  car- 
ries forward  the  motion  lost  by  the  former.  There  can 
be  no  suspended  animation  among  inanimate  bodies. 

Thus  we  find  no  difficulty  in  tracing  what  appears  to 
be  latent  or  suspended  motion.  For  example,  as  before 
shown,  though  water  and  ice  may  both  exist  at  32°, 
they  are  by  no  means  in  the  same  condition.  The 


88  SOLAR    HEAT. 

molecules  in  the  water  have  a  motion  which  differen- 
tiates the  water  from  the  ice,  and  which  they  retain 
so  long  as  the  water  exists  in  liquid  form.  This  motion 
of  liquidity  was  communicated  to  the  water  at  the 
moment  of  melting,  and  is  exactly  equal  to  the  amount 
of  heat  then  apparently  becoming  latent.  When  the 
water  is  again  congealed,  this  motion  cannot  exist 
in  the  ice,  but  continue  it  must  in  some  form,  and 
therefore  reappears  as  heat  from  arrested  motion. 
Therefore  Judge  Stallo's  aphorism,  before  quoted,  that 
"  all  potential  energy,  so-called,  is  kinetic,"  seems  to  be 
undeniable. 

There  is,  however,  a  different  sense  in  which  some 
forms  of  energy  may  properly  be  said  to  be  potential ; 
that  is,  capable  of  doing  work,  though  not  at  present  so 
employed,  in  distinction,  not  from  kinetic,  but  from 
working  force. 

The  best  possible  illustration  of  this  is  found  in  the 
tangential  and  centripetal  motions  of  the  earth.  The 
tangential  simply  perpetuates  the  motion  once  imparted 
to  it,  and  the  earth  will  move  forever  in  obedience  to 
it,  unless  stopped  by  some  obstacle,  according  to  New- 
ton's first  law. 

But  this  motion  has  not  gone  to  rest.  It  is  as  actual 
and  as  active  as  when  first  exerted.  The  centripetal 
force  or  gravitation,  on  the  contrary,  is  obliged  to  over- 
come the  inertia  of  the  whole  mass  of  the  earth  every 
instant.  It  changes  the  line  of  the  earth's  motion  from 
moment  to  moment.  This  is  work  (Mid  plenty  of  it, 
and  the  force  therefore  requires  constant  renewal. 

The  only  distinction,  then,  is  between  energy  or 
motion  changing  and  not  changing  its  subject.  But  if 
by  potential  energy  is  meant  a  future  possible  motion 


POTENTIAL    ENERGY.  OW 

not  now  in  existence,  this  motion,  whenever  it  does 
come  into  existence,  would  of  necessity  be  a  new  crea- 
tion. 

There  is  nothing  novel  in  the  proposition  that  no 
particle  or  mass  in  motion  can  cease  to  move  except  by 
communicating  this  motion,  transformed  or  untrans- 
formed,  to  some  other  particle  or  mass,  unless  it  is  the 
emphasis  and  persistency  with  which  the  proposition  is 
here  insisted  upon.  Yet  it  is  absolutely  fatal  to  the 
doctrine  of  potential  energy,  in  the  sense  of  suspended 
motion,  or  energy  not  in  action.  It  is  a  simple  truism 
to  assert  that  whenever  the  subject  of  a  motion  ceases 
to  act,  without  transferring  its  motion  to  some  other 
object,  if  that  were  conceivable,  then  the  motion  ceases 
absolutely  to  exist.  It  is  not  in  its  last  abode,  and  has 
found  no  new  one.  Where,  then,  is  it?  Evidently, 
nowhere.  It  cannot  be  revived  except  by  a  new  creation. 
But  a  new  creation  is  not  a  revival  of  a  preexistent 


*  NOTE.— Since  writing  this  chapter,  S.  Tolver  Preston's  "Physics  of  the 
Ether  "  has  fallen  under  my  notice.  It  is  largely  devoted  to  disproving  poten- 
tial energy  and  action  at  a  distance.  I  will  transcribe  two  or  three  sentences 
from  page  9: 

"In  fact,  this  theory  of  the  existence  of  'potential  energy,' or  an  energy 
without  motion^  in  regard  to  vagueness,  cannot  be  said  to  differ  from  the  theory 
of  '  action  at  a  distance,'  which  it  is  intended  to  support,  the  same  system  of 
procedure  being  adopted,  viz. :  that  of  assuming  a  thing  to  be  practicable  where 
the  sole  ground  upon  which  the  assumption  as  to  practicability  can  rest  —  a 
conception  of  the  means  —  is  wanting." 

"  The  very  assumption  of  the  existence  of  energy  in  a  double  form  (poten- 
tial and  kinetic),  or  the  attempt  to  attach  two  ideas  to  the  fundamental  concep- 
tion of  energy,  or  to  assume  that  two  kinds  of  energy  exist  (potential  and 
kinetic),  cannot  but  be  regarded  by  itself  as  sufficiently  questionable." 


CHAPTER  XI. 

CONSERVATION  OF  ENERGY. 

Myriads  of  viewless  instruments,  the  springs 
By  which  the  eternal  round  of  life  goes  on. 

—  PERCIVAL. 

THE  word  "loss"  should  be  eliminated  from  the 
vocabulary  of  science,  and  the  word  "transfer- 
ence" substituted  in  its  place.  The  doctrine  of  conser- 
vation means  this  or  it  means  nothing.  Energy,  of  which 
heat  is  one  of  the  forms,  is  not  matter,  but  it  is  a  quan- 
tity which  can  be  measured,  transferred  and  trans- 
formed, though  it  can  neither  be  created,  annihilated 
nor  lost.  Although  heat  is  not  matter,  it  is  a  condition 
of  matter,  and  is  inseparable  from  it.  It  cannot  exist 
apart  from  matter,  neither  can  it  be  confined  to  any 
particular  region  or  body. 

The  quantity  of  heat  in  the  sun  at  any  given  moment 
may  be  computed.  At  the  next  moment,  if  heat  has 
left  the  sun  in  the  meantime,  as  it  certainly  has  in  large 
quantities,  the  amount  left  will  be  less,  unless  there 
has  been  an  accession  at  the  same  time  of  an  equal 
amount. 

A  very  small  stream  can  flow  from  a  very  large  res- 
ervoir for  a  long  time  before  the  reservoir  will  be 
exhausted.  But  a  very  large  stream  cannot  now  even 
from  a  very  large  reservoir  without  speedy  exhaustion. 
Take,  for  example,  a  cubic  cistern  of  water  of  any  size, 
situated  upon  an  elevation,  and  remove  the  whole  of 


CONSERVATION    OF    ENERGY.  91 

one  side ;  it  will  not  be  long  in  emptying  itself.  If  the 
water  possessed  the  property  of  flowing  with  equal  ease 
and  rapidity  in  all  directions,  upward,  downward  and 
laterally,  and  the  top,  bottom  and  sides  of  the  cistern 
were  simultaneously  removed,  how  long  would  the  res- 
ervoir last,  if  unreplenished  ? 

The  heat  of  the  sun  is  not  material  like  water,  but  it 
flows  forth  from  the  sun  on  all  sides  with  inconceivably 
greater  velocity  and  in  correspondingly  greater  quanti- 
ties, and  must  be  replenished  in  equal  proportion,  or  be 
exhausted.  But  has  not  the  sun  an  almost  inexhaustible 
source  of  supply  in  potential  energy,  turning  to  kinetic 
energy  in  the  form  of  sensible  heat  ?  Science  knows  of 
no  such  inexhaustible  fountain.  Almost  the  only  repos- 
itories of  potential  energy,  so-called,  in  the  earth  are 
found  in  her  coal  measures,  oil  wells,  peat  beds  and 
forests ;  in  a  word,  in  her  unoxiclized  carbon.  The  sun 
no  doubt  contains  vast  quantities  of  unoxidized  carbon, 
silicon,  metals  and  other  combustibles,  but  they  are  not 
available  for  the  production  of  heat,  because  they  are 
already  too, hot  to  burn.  They  add  nothing  to  the  heat 
of  the  sun,  but  on  the  contrary,  as  these  substances  are 
constantly  radiating  heat,  they  require  constant  acces- 
sion of  equal  amounts  to  keep  up  their  temperature 
unchanged.  The  sun  is  not  a  "  self-feeder "  any  more 
than  the  stoves  so  misnamed.  We  come  back  to  our 
place  of  starting ;  energy  is  generated  nowhere ;  it  is 
lost  nowhere ;  it  is  confined  to  no  place ;  it  travels  end- 
lessly from  world  to  world  and  from  sun  to  sun ;  it 
never  tires;  it  never  rests;  it  never  begins;  it  never 
ends ;  it  never  increases ;  it  never  grows  less.  It  is  at 
once  the  symbol  of  omnipotence  and  of  eternity.  The 
universe  can  never,  never,  never  run  down.  The  idea 


tfZ  SOLAR    HEAT. 

in  the  present  state  of  science  is  an  inconceivable  impos- 
sibility. The  universe,  as  a  whole,  is  a  self-winding 
horologe,  but  no  part  is  independent  of  the  rest.  Parts 
may  become  congealed  by  the  transference  of  their 
heat,  but  other  parts  will  at  the  same  time  gain  heat  to 
the  same  extent.  In  the  never  ending  cycles  of  infinite 
ages,  particular  suns  or  worlds  may  at  different  periods 
vary  from  hot  to  cold,  and  from  cold  to  hot  (though  I 
know  of  no  reason  why  our  sun  should  ever  become 
cooler),  but  energy  remains  the  same  from  age  to  age. 


CHAPTER  XII. 

DISSIPATION  OF  ENERGY. 

Eterne  alternation 

Now  follows,  now  flies.  — EMERSON. 

IT  is  a  familiar  fact  in  physics  that  motion  is  readily 
convertible  into  heat.  Anyone  who  has  ridden  on  a 
railway  car  knows  how  often  it  becomes  necessary,  in 
long  hauls,  to  stop  and  extinguish  the  fires  of  heated 
axles.  This  is  simply  mechanical  motion  converted  into 
heat.  This  process,  in  multiplied  forms,  is  going  for- 
ward all  around  us  to  a  vast  extent  and  with  the  greatest 
facility. 

But  to  recover  this  heat  and  reconvert  it  into  mechan- 
ical force  seems  not  so  easy ;  "  HOG  opus,  hie  labor  est" 
This  alarming  fact  has  enlisted  the  special  attention  of 
such  distinguished  men  as  Sir  Win.  Thomson,  Joule, 
Rankine,  Clausius,  Tait,  Maxwell,  and  many  others,  but 
no  satisfactory  remedy  has  been  found. 

On  the  contrary,  it  seems  to  be  conceded  that  all 
forms  of  energy  are  gradually  turning  to  heat,  and  this 
heat  is  becoming  universally  diffused,  only  a  small  per- 
centage of  it  being  restored  to  the  form  of  mechanical 
motion.  In  other  words,  the  scientists  seem  bent  on 
realizing  a  universal  Tartarus,  at  the  same  time  that 
even  a  limited  one  is  growing  in  disfavor  with  the 
theologians. 

The  eloquent  writer,  Balfour  Stewart,  says  in  his 
" Conservation  of  Energy,"  page  142:  "Now,  if  this 

93 


94:  SOLAR   HEAT. 

process  goes  on,  and  always  in  one  direction,  there  can 
be  no  doubt  about  the  issue.  The  mechanical  energy 
of  the  universe  will  be  more  and  more  transformed  into 
universally  diffused  heat  until  the  universe  will  no 
longer  be  a  fit  abode  for  living  beings.  The  conclusion 
is  a  startling  one." 

I  admit  freely  that  I  have  not  the  time  nor  the  facil- 
ities to  engage  in  the  investigations  that  would  qualify 
me  to  meet  these  eminent  men  on  their  own  ground. 
But  this  need  not  prevent  me  from  offering,  for  their 
consideration,  a  suggestion  that  may  lead  to  a  solution 
of  the  difficulty  and  extend  the  lease  of  life  allowed  to 
our  system. 

Nature  has  broad  fields  for  the  exercise  of  her  powr- 
ers,  and  resources  for  the  accomplishment  of  her  pur- 
poses of  which  "we  little  reck."  The  broadest  of  all 
fields  is  the  universal  ether.  In  this  may  be  going 
forward  processes  of  which  we  do  not  dream.  Is  it  not 
just  possible  that  this  universal  ether  may  have  a  duty 
to  perform  in  the  matter  of  restoring  that  equilibrium 
between  heat  and  mechanical  force,  wrhich  other  agen- 
cies are  busy  destroying? 

The  vibrations  of  ether  are  supposed  to  be  different 
in  kind  for  the  different  kinds  of  energy.  But  it  is 
possible  that  the  difference  may  be  more  in  degree  than 
in  nature.  Those  by  which  light  and  heat  are  trans- 
mitted are  said  to  be  transverse  to  the  line  of  propaga- 
tion. Some  have  compared  them  to  the  running  waves 
of  a  rope  switched  up  and  down  by  a  child  in  play. 
(See  Fig.  2.) 

This  form  of  wave  had  amplitude  or  transverse 
dimension,  as  well  as  wave  length  from  crest  to  crest. 
If  the  amplitude  were  all  gone  or  dwindled  to  an  infi- 


DISSIPATION    OF    ENERGY. 


95 


nitesimal  quantity,  we  should  then  have  only  the  wave 
length  left,  or  a  molecular  vibration  backward  and 
forward,  similar  to  the  wave  motion  of  air  and  musical 
strings.  (I  speak  by  way  of  suggestion,  and  not  ex 
cathedra.}  But  this  is  the  nature  of  the  vibrations  of 
mechanical  force. 


lA/1 


FIG.  2. 


Now  the  grand  bodies  of  the  universe  are  certainly 
the  suns.  They  also  are  the  grand  centres  of  every 
form  of  energy.  But  they  are  all  superlatively  super- 
heated bodies,  and  give  off  their  vibrations  in  waves  of 
amplest  amplitude,  or  in  the  form  of  light  and  heat. 

Now,  may  we  or  may  we  not  suppose  that  these  waves, 
in  their  extended  travels  (waves  travel  but  not  the 
ether),  lose  somewhat  of  their  amplitude  and  approach 
the  condition  of  backward  and  forward  motion  only? 
If  so,  those  rays  that  come  from  an  infinite  distance 
will  have  their  amplitudes  reduced  to  an  infinitesimal 
amount,  and  will  be  known  only  or  mainly  as  waves  of 
mechanical  force,  while  those  coming  from  the  nearer 
suns  will  have  the  greater  amplitude,  and  will  retain 
their  Promethean  character  of  fire  bearers.  This  does 
not  involve  in  the  least  the  idea  that  any  energy  is  lost, 
but  only  changed  to  another  form. 

But  granting  that  waves  of  heat  change  to  mechani- 


96  SOLAR    HEAT. 

cal  force  on  the  wing,  as  the  harlequin  changes  his  toilet 
while  flying  round  the  ring,  this  avails  nothing,  except 
to  supply  the  needed  force  for  gravitation,  unless 
changed  back  again  to  heat  on  reaching  the  suns. 

How  the  rays  of  heat  change  to  waves  of  mechanical 
force  may  not  be  susceptible  of  explanation,  unless  the 
following  may  pass  for  such :  Thus,  heat,  like  all  radiant 
forces,  diffuses  itself  as  the  square  of  the  distance 
increases.  This  rate  of  dispersion  continues  forever. 
The  necessary  effect  of  this  dispersion  is  to  weaken  or 
lower  the  intensity  of  these  waves.  But  the  wave  length 
and  velocity  undergo  no  diminution.  The  diminution 
in  intensity  by  diffusion,  therefore,  must  of  necessity  be 
accomplished  by  a  corresponding  reduction  in  wave 
amplitude. 

If  "  dissipation "  of  energy  means  diffusion,  we  can 
readily  admit  it,  because  if  all  the  heat  from  one  sun  is 
diffused  through  the  whole  of  space,  so  is  the  heat  from 
every  other  sun,  the  result  of  which  is  to  pack,  if  we 
may  use  the  expression,  every  cubic  inch  of  ether  as 
solidly  with  heat  vibrations  as  the  portions  that  lie  in 
immediate  contact  with  the  suns.  But  if  the  word 
"  dissipation "  is  used  to  denote  loss  or  destruction  of 
energy,  it  is  impossible,  because  the  grand  totality  of 
energy  is  forever  conserved. 

The  real  cause  of  the  alarming  danger  to  which  we 
are  exposed  is  the  rapid  exhaustion  of  our  forests,  coal 
beds  and  oil  wells.  These  are  almost  our  only  resources 
for  artificial  heat,  our  only  remaining  one  being  the 
inexhaustible  sun.  These  treasures  of  chemical  heat 
have  been  stored  away  only  by  the  slow  action  of  sun- 
light and  heat  operating  upon  the  dioxide  of  carbon  in 
the  air,  through  immensely  long  periods  of  time, 


DISSIPATION    OF    ENERGY.  9Y 

What  shall  we  do  when  these  are  exhausted,  as  they 
must  be  in  a  very  few  centuries  at  the  present  rate  of 
destruction?  This  is  a  momentous  question,  but  we 
will  not  despair  of  an  answer. 

This  is  the  age  of  reckless  extravagance  and  profligate 
waste.  But  the  world  is  yet  in  its  youth,  with  manj 
of  the  follies  of  youth  remaining.  It  will  surely  be- 
come wiser  as  it  grows  older,  and  the  golden  age  will 
again  return  to  earth.  But  how?  By  wisdom,  by 
sobriety,  by  industry,  by  economy.  Who  shall  say  that 
these  are  not  more  conducive  to  well  being  and  happi- 
ness than  their  opposities  ? 

In  the  coming  golden  age  men  will  not  all  rush  to 
large  cities  to  burn  the  candle  of  life  at  both  ends  in  the 
hotbeds  of  dissipation  and  the  fierce  struggle  for  unearned 
wealth.  A  farm  of  100  acres,  and,  perhaps  less,  will 
suffice  for  a  single  family,  and  a  third  of  this  will  be 
permanently  devoted  to  arboriculture.  Fifty  trees  will 
supply  fuel  for  a  year  and  fifty  young  trees  will  take 
their  place. 

But  will  mankind  ever  return  to  these  simple  and 
primitive  modes  of  life?  Not  the  present  generation 
nor  its  immediate  successors;  not  until  compelled  by 
the  loss  of  a  large  part  of  our  rich  inheritance,  will  the 
race  return  to  habits  of  simplicity,  industry  and  econ- 
omy; but  when  so  compelled,  will  they  not  be  wiser, 
better  and  happier? 

In  the  good  time  coming  every  man  and  woman  will 
not  seek  to  shirk  their  share  of  the  hard  work  of  life 
and  live  off  the  labors  of  others.  The  earth,  used  for 
the  comfort  and  convenience  of  man,  but  not  abused, 
will  yield  its  fruits  without  exhaustion.  Every  home 
will  be  surrounded  by  groves ;  every  hillside  will  wave 
7 


98  SOLAR    HEAT. 

in  verdure.  Rills,  rivulets  and  rivers  will  flow  through 
lands  now  parched  and  barren.  Arboriculture  is  now 
the  hope  of  the  world. 

Then  let  us  pray  that  come  it  may  — 

As  come  it  will  for  a'  that — 
That  sense  and  mirth  o'er  a'  the  earth 

May  bear  the  gree  *  and  a'  that. 
For  a'  that,  and  a'  that, 

It's  coming  yet  for  a'  that, 
That  man  to  man,  the  warrald  o'er, 

Shall  brothers  be  for  a'  that.  — BURNS. 

#  Victory, 


PART  II. -GRAVITATION. 


CHAPTER  I. 

GRAVITATION— ITS  NATURE  AND  CAUSE. 

Shall  the  great  soul  of  Newton  quit  the  earth, 

To  mingle  with  his  stars ;  and  every  muse, 

Astonished  into  silence,  shun  the  weight 

Of  honors  due  to  his  illustrious  name?          —THOMSON. 

~TT7"E  owe  a  sacred  allegiance  to  truth  from  which 
VV  the  authority  of  no  name,  however  illustrious, 
can  absolve  us.  Should  we  even  find  errors  associated 
with  the  name  of  Newton,  as  spots  have  been  discov- 
ered on  the  sun,  it  would  still  be  our  duty  to  acknowl- 
edge the  former,  as  much  as  it  was  Galileo's  to  avow 
the  latter.  Fortunately  for  the  writer,  he  is  not 
required  to  antagonize  any  tiling  that  Newton  has 
taught,  but  rather  finds  it  his  pleasing  duty  to  follow 
out  hints  given  by  the  great  master,  pointing  toward 
the  doctrine  here  advanced. 

He  did  not  profess  to  have  discovered  the  cause  of 
gravitation,  neither  has  he  left  on  record  any  command 
forbidding  the  further  study  of  the  subject  by  others. 

We  owe  the  discovery  of  the  law,  not  the  cause,  of 
gravitation,  to  the  transcendent  genius  of  Newton. 
Though  generalized  from  the  observation  of  two  objects 
only,  an  apple  and  the  moon,  the  conception  is  one  of 
the  grandest  —  perhaps  the  very  grandest  —  that  has 


100  GRAVITATION. 

ever  entered  the  mind  of  man.  It  seems  impossible 
that  the  grandeur  and  comprehensiveness  of  this  law 
could  have  entered  the  human  mind  except  by  a  reve- 
lation. 

Though  revelations  in  religion  are  now  at  a  discount, 
revelations  in  science  are  still  in  order.  Though  it  is 
only  the  high  priests  of  science  that  are  authorized  to 
speak  authoritatively  in  her  name,  yet  the  humblest 
servitor  at  her  shrine  may  point  a  finger  in  the  direction 
of  her  penetralia. 

The  popular  conception  of  gravitation  is  that  every 
particle  of  ordinary  matter,  by  virtue  of  an  inherent 
energy,  reaches  forth  and  lays  hold  of  every  other  par- 
ticle of  matter  in  the  universe,  and  draws  the  same 
toward  itself.  Almost  the  keystone  of  this  theory, 
however,  was  knocked  out  by  Newton  himself,  who 
denied  with  emphasis  the  possibility  of  such  an  energy 
as  residing  in  the  particles  of  matter.  If  we  can  con- 
ceive of  anything  more  wonderful  than  this  conception, 
it  will  certainly  be  the  modified  one  most  deferentially 
here  presented.  This  theory  (for  we  will  claim  no 
higher  character  for  it  at  present)  we  will  consider 
under  two  divisions:  1.  The  efficient  cause  which 
Newton  left  —  and,  2.  The  mode  of  its  operation. 

1.  The  force  of  gravitation  we  would  locate  in  the 
universal  ether  in  the  form  of  waves,  vibrations  or  rays 
of  mechanical  force,  proceeding  with  the  rapidity  of 
light  in  all  possible  directions  in  straight  lines  and  with- 
out interference  with  each  other.  These  waves,  though 
the  proximate,  are  not  the  original  cause  of  this  force ; 
one  step  further  back,  and  we  shall  find  that  all  the 
vibrations  which  constitute  these  waves  have  been 
injected  into  the  universal  ether  by  universal  matter, 


GRAVITATION ITS    NATURE    AND    CAUSE.  101 

and  thus  pass  from  matter  to  ether  and  from  ether  to 
matter  in  an  unending  cycle,  the  beginning  of  which 
is  coeval  with  the  beginning  of  all  things. 

This  ethereal  ocean,  in  which  we  may  affirm,  without 
irreverence,  that  all  things,  including  all  forms  of 
energy,  "live  and  move  and  have  their  being,"  is  an 
archipelago,  whose  islands  are  blazing  suns  and  whose 
sands  are  the  lesser  stars.  The  waves  of  this  ocean  do 
not  quench,  but  feed  and  fan  their  flames. 

Whether  the  theory  here  advanced  shall  stand  or 
fall,  the  objective  reality  of  these  ethereal  waves  of 
mechanical  force  will  be  conceded  by  all,  after  reading 
the  quotations  in  the  next  chapter.  So  much  for  the 
present  as  to  the  source  of  gravitation. 

2.   As  to  the  mode  of  its  operation : 

From  the  very  definition  of  these  propulsive  waves 
as  propagated  in  straight  lines  in  all  possible  directions, 
without  interference  with  each  other,  it  follows  that 
they  will  impinge  and  press  equally  on  all  sides  of 
every  particle,  except  in  so  far  as  these  waves  may  be 
intercepted  from  one  particle  by  some  other  particle  or 
particles.  It  goes  without  saying  that  every  individual 
particle  will  intercept  more  or  less — generally  less— 
of  this  force  from  every  other  particle  in  the  universe. 
In  other  words,  each  particle  surrounds  itself  by  a 
shadow  or  negation  of  force  growing  thinner  as  the 
square  of  the  distance  increases,  but  extending  to 
infinity. 

This  may  be  illustrated  by  a  couple  of  points  repre- 
senting a  couple  of  particles,  and  a  very  small  pencil  of 
rays  intercepted  by  particle  P,  from  particle  E,  and 
vice  versa. 

Let  A  B  G  D,  in  the  figure,  represent  the  celestial 


102 


GRAVITATION. 


concave  as  to  particle  E.  All  the  rays  from  the  hemi- 
sphere A  D  C,  falling  on  particle  E^  will,  by  direct  or 
resultant  motion,  tend  to  push  this  particle  toward  par- 
ticle J\  and  all  the  rays  from  hemisphere  A.  £  C, 
except  those  'intercepted  by  particle  P,  will,  in  like 
manner,  tend  to  drive  it  in  the  opposite  direction.  It  is 


manifest  that  a  diverging  pencil  has  been  intercepted 
from  E  by  particle  jP,  and  particle  E  being  to  this 
extent  unsupported  on  the  side  toward  P,  has  a  ten- 
dency to  fall  in  that  direction  on  the  line  of  the  least 
resistance,  and,  vice  versa,  P  has  an  equal  tendency  to 
fall  toward  E. 


GRAVITATION ITS    NATURE    AND    CAUSE.  103 

It  will  be  seen  by  the  figure  that  even  the  infinites- 
imal particles  are  regarded  as  having  volume  relatively 
to  the  infinitely  fine  lines  of  force  by  which  they  are 
assailed,  so  that  the  farther  the  particle  E  is  from  P, 
the  fewer  will  be  the  number  of  rays  intercepted  by  P 
from  E)  and  vice  versa. 

From  the  doctrine  of  gravitation,  when  fully  devel- 
oped, it  will  be  found  that  the  ultimate  particles  of 
matter  not  only  possess  volume,  but  are  spherical  in 
form.  The  result  is  that  the  force  tending  to  impel  any 
two  particles  or  aggregations  toward  each  other  will 
vary  inversely  as  the  square  of  the  distance. 

I  have  thus  endeavored,  by  a  brief  description  rather 
than  by  a  concise  definition,  to  state  the  nature  and 
modus  operandi  of  the  force  of  gravitation. 

A  definition  might  be  given  in  this  form : 

1.  Every  particle  of  matter  in  the  universe  is  the 
centre  of  a  concourse  of  propulsive  forces  pressing  it 
equally  on  all  sides,  except  where  intercepted  from  it 
by  some  other  particle  or  mass,  and  vice  versa.     These 
mutually  intercepted  forces  will  vary  directly  as  the 
product  of  the  intercepting  masses  divided  by  the  square 
of  the  distance  separating  them. 

2.  Every  particle  and  mass  tends  to  approach  every 
other  on  the  lines  of  least  resistance. 

Or,  more  briefly,  thus :  Every  particle  of  matter  in 
the  universe  is  impelled  toward  every  other  particle  by 
propulsive  forces  varying  directly  as  the  masses  and 
inversely  as  the  square  of  the  distance  between  their 
centres. 

Every  particle,  though  so  minute  that  no  microscope 
can  detect  it,  nor  even  imagination  form  an  image  of  it, 
nevertheless  casts  its  shadow  upon  every  other  particle 


104  GRAVITATION. 

in  the  universe,  thus  depriving  it  of  a  portion  of  the 
force  it  would  otherwise  receive  on  that  side,  and  so 
creating  a  tendency  on  the  part  of  the  particle  in  the 
shadow  to  fall  toward  the  one  casting  the  shadow,  and 
vice  versa.  This  is  wonderful  almost  to  the  verge  of 
incredibility,  but  not  a  whit  more  incredible  than  the 
doctrine  that  each  particle  reaches  out  an  arm  of  force 
to  every  other  particle  in  the  universe,  lays  hold  of  and 
draws  the  same  toward  itself. 

There  is  no  known  or  possible  mode  by  which  one 
particle  or  mass  can  act  upon  another  mechanically,  but 
by  a  push  or  a  pull.  But  Newton  has  denied  to  the 
particles  the  power  to  exercise  a  pull,  and  asserts  that 
all  force  is  propulsive,  or  "vis  a  tergo"  This  settles 
the  question,  so  far  as  the  authority  of  Newton  can  go, 
that  gravitation  is  effected  by  a  push  and  not  by  a  pull. 

A  wide  distinction  is  to  be  observed  between  the 
action  of  different  particles  in  originating  these  waves 
and  in  intercepting  them.  In  originating  these  waves 
some  particles  act  with  great  energy,  some  with  very 
little,  and  those  at  the  zero  of  temperature,  if  any,  exert 
none  at  all.  On  the  contrary,  every  particle  intercepts 
exactly  the  same  quantity  of  mechanical  force,  regard- 
less of  its  condition. 

Again,  that  wonderful  condition  of  the  ether,  by 
virtue  of  which  it  acts  simultaneously  in  all  directions, 
is  the  combined  result  of  the  motions  of  every  particle 
in  the  universe,  while,  in  intercepting  this  force,  every 
material  particle  acts  with  absolute  independence  of 
every  other. 

Another  fact  follows,  of  course.  As  each  particle  of 
matter  intercepts  one  unit  of  force  only,  all  the  remain- 
ing force  in  each  successive  wave  moves  onward  without 


GRAVITATION ITS    NATURE    AND    CAUSE.  105 

impediment  through  all  bodies,  no  matter  how  hard  or 
how  dense,  and  in  all  possible  directions  as  freely  as 
through  the  intangible  ether.  Other  facts  in  regard  to 
this  force  will  find  their  place  more  appropriately  in 
other  connections. 

These  facts  are  easily  remembered,  and  are  indispen- 
sable to  a  correct  conception  of  the  force  of  gravitation 
as  here  proposed.  I  trust  I  have  made  myself  intelligi- 
ble to  my  readers,  so  far  as  concerns  the  mere  statement 
of  the  theory.  Its  illustration  and  proof  are  quite  dif- 
ferent matters. 


CHAPTER  II. 

ILLUSTRATIONS  OF  GRAVITATION.— AUTHORITIES. 

By  no  other  arrangement  have  I  been  able  to  find  so  admirable 
a  symmetry  of  the  universe,  and  so  harmonious  a  connection  of 
orbits,  as  by  placing  the  lamp  of  the  world,  the  sun,  in  the  midst  of 
the  beautiful  temple  of  nature,  as  on  a  kingly  throne,  ruling  the 
whole  family  of  circling  stars  that  revolve  around  him. 

— COPERNICUS. 

IT  has  seemed  to  me  that  we  might  gradually  approach 
the  consideration  of  this  profoundest  problem  in 
nature  by  illustrations  on  a  level  with  the  most  ordinary 
understanding. 

It  is  manifest,  without  argument,  that  the  position  of 
all  the  heavenly  bodies,  so  far  as  gravitation  is  con- 
cerned, can  be  produced  by  universal  and  self-neutral- 
izing repulsion  as  easily  as  by  universal  and  self- 
neutralizing  attraction. 

To  illustrate :  Let  a  large  round  table  be  placed  in 
the  middle  of  a  room ;  place  a  wooden  globe  in  the 
centre  with  any  number  of  equidistant  radii,  composed 
of  rigid  rods,  projecting  from  its  equator.*  Station 
around  it  an  equal  number  of  boys  of  exactly  equal 
strength,  one  to  each  rod.  No  matter  whether  they  all 
push  or  pull,  the  pushes  or  pulls  will  neutralize  each 
other  and  the  globe  will  remain  unmoved.  But  this  is 
not  the  case  with  the  earth.  She  is  slowly,  compared 
with  her  onward  motion,  falling  toward  the  sun.  Why 

*  NOTE.— A  better  illustration  would  show  the  rods  projecting  from  every 
point  on  the  globe. 

106 


ILLUSTRATIONS    OF    GRAVITATION.  107 

she  does  not  actually  reach  the  sun  will  be  explained 
hereafter.  If  we  suppose  the  boys  to  be  pushing  upon 
this  wooden  globe,  we  must,  to  adapt  the  comparison  to 
the  case  in  hand,  withdraw  one  of  the  boys,  say  from 
the  south  side  of  the  table;  then  if  all  the  remaining 
boys  push  with  equal  force,  the  globe  will  slowly  move 
toward  the  side  of  the  table  where  the  resistance  is  the 
smallest-. 

We  will  now  transfer  the  scene  to  the  heavens,  and 
suppose  the  earth  to  take  the  place  of  the  globe,  and 
the  bodies  which  occupy  the  starry  concave  to  represent 
the  boys  in  the  illustration,  the  sun  occupying  the  neg- 
ative position  of  the  boy  removed. 

We  will  suppose  these  celestial  bodies,  except  the 
sun,  to  be  sending  out  obscure  rays  of  mechanical  force 
in  all  possible  directions.  All  these  rays  impinge  upon 
the  earth  on  every  side,  except  the  comparatively  small 
portion  intercepted  by  the  sun.  This  is  the  weak  spot 
in  the  heavens  toward  which  the  earth  is  slowly  impelled 
by  what  is  called  gravitation.  The  sun,  the  earth,  and 
probably  every  inhabitant  of  the  heavens,  are  moving 
in  their  orbits  by  an  un wasting  tangential  force.  In 
this  motion  they  encounter  practically  no  resistance,  do 
no  work,  suffer  no  retardation,  at  least  none  that  is  per- 
ceptible. They  undergo  no  cooling  nor  loss  of  energy 
of  any  kind,  and  of  course  communicate  no  heat  nor 
other  motion  to  other  suns  or  worlds.  As  this  force 
suffers  no  diminution,  it  requires  no  renewal.  It  is, 
however,  a  most  real  force,  as  would  become  unpleas- 
antly manifest  to  us  if  our  earth  should  collide  with 
another  voyager  through  space  of  equal  mass,  and 
moving  with  equal  velocity  in  an  opposite  direction. 

The  centripetal  force  or  gravitation  is  just  the  reverse. 


108  GRAVITATION. 

It  is  constantly  doing  work.  It  is  at  every  moment 
overcoming  the  inertia  of  the  earth,  changing  its  direc- 
tion and  bending  the  straight  line  of  its  tangential 
motion  into  the  curved  line  of  its  orbit.  Not  only  the 
small  portions  that  encounter  the  earth  and  other  plan- 
ets in  their  orbits,  but  the  immeasurably  greater  por- 
tions, which  go  on  and  impinge  on  our  sun  and  other 
distant  suns  in  equal  exchange,  are  constantly  doing 
work.  It  is  a  kinetic  or  advancing  force.  It  rests  not 
even  at  the  sun,  but  is  ever  marching  on.  It  doubtless 
helps  to  swell  the  outflowing  streams  of  light  and  heat 
wThich  are  constantly  pouring  forth  from  the  sun.  It 
requires  to  be  renewed  from  moment  to  moment.  But 
a  force  that  is  renewed  every  moment  necessarily  moves 
in  a  circuit.  This  force  leaves  a  legacy  of  cold  or 
exhaustion  in  the  bodies  that  act  as  senders,  but  confers 
increased  activity,  either  in  the  form  of  mechanical 
motion  or  heat,  upon  the  bodies  which  act  as  receivers. 
But  as  all  bodies  are  both  senders  and  receivers,  the 
distribution  remains  the  same,  while  the  circuit  is 
eternal. 

Nature  seems  to  have  one  policy  in  regard  to  light 
and  heat,  that  of  unequal  distribution.  To  effect  this 
unequal  distribution  she  has  sprinkled  space  with 
hot  and  cold  bodies,  the  former  immense  in  size,  the 
latter  comparatively  small,  and  this  relative  condition  is 
maintained  by  means  that  I  have  endeavored  to  explain 
in  Part  First  of  this  work.  The  heated  bodies  or  suns 
remain  permanently  and  inconceivably  hot,  and  the 
cooler  bodies  or  planets  and  satellites  remain  perma- 
nently, comparatively  cold. 

But  in  regard  to  mechanical  force  nature  has  adopted 
precisely  an  opposite  policy,  that  of  perfectly  equal  dif- 


ILLUSTRATIONS    OF    GRAVITATION.  109 

fusion.  It  is  everywhere  equally  distributed  through- 
out space,  and  ready  at  every  point  to  do  its  appropriate 
work,  pressing  equally  in  all  directions,  except  where 
intercepted.  But  a  large  body  like  the  sun,  and  smaller 
ones  in  proportion,  intercept  many  of  these  rays  of 
force  moving  in  all  directions,  and  consequently  on  all 
sides  of  the  sun  there  is  a  partial  vacuum  of  force, 
diminishing  outwardly  in  amount  as  the  squares  of  the 
distances  increase.  This  partial  vacuum,  which  sur- 
rounds the  sun  and  all  other  bodies,  is  the  negation  of 
force,  which,  in  concert  with  the  positive  force  coming 
from  the  opposite  direction,  constitutes  the  force  of 
gravitation. 

We  have  only  to  add  that  these  waves  of  force  are 
dynamic  in  character  and  regard  mass  only  and  not 
volume.  Therefore  the  negative  force  by  which  the  sun 
acts  upon  the  earth  is  equal  to  the  number  of  molecules 
in  the  sun  multiplied  by  the  number  of  molecules  in  the 
earth  and  divided  by  the  square  of  the  distance ;  that  is, 
each  molecule  in  the  sun  stops  one  unit  of  mechanical 
force  from  reaching  every  molecule  in  the  earth,  and 
every  molecule  in  the  earth  performs  exactly  the  same 
service  for  every  molecule  in  the  sun,  and,  therefore,  the 
earth  and  sun  respectively,  on  the  sides  turned  toward 
each  other,  are  to  that  extent  unsupported,  and  to  the 
same  extent  are  pushed  toward  each  other. 

The  same  law  will  hold  good  throughout  the  \vhole 
realm  of  nature  between  all  bodies,  large  and  small ;  in 
fact,  it  is  identical  with  the  law  of  universal  gravitation, 
but  acting  by  propulsion  instead  of  traction. 

Gravitative  force,  which  most  certainly  exists  and 
operates  throughout  space,  is  possible,  according  to  this 
law,  acting  by  means  of  vibrations  through  a  known 


110  GRAVITATION. 

medium.  But  if  we  deny  to  gravitation  the  use  of  the 
common  ether,  free  to  all  other  forms  of  energy,  we 
compel  it  to  "  act  at  a  distance ''  without  an  intervening 
medium,  a  thing  now  conceded  to  be  an  impossibility. 
In  fact,  this  was  pronounced  to  be  impossible  as  long 
ago  as  the  time  of  Newton,  and  on  no  less  an  authority 
than  that  of  the  master  himself,  as  we  shall  soon  see. 

This  is  the  theory  of  gravitation  most  respectfully 
submitted  to  the  consideration  of  the  learned  public, 
and  we  earnestly  beg  the  candid  reader  not  to  dismiss  it 
with  a  sneer  until  he  has  examined  carefully  all  the 
arguments,  pro  and  con,  to  which  we  shall  invite  his 
attention. 

In  support  of  this  view  I  shall,  before  advancing 
any  arguments  of  my  own,  introduce  a  few  quotations. 
I  quote  first  from  "Science  in  Short  Chapters,"  by 
W.  M.  Williams,  page  112,  American  edition : 

"The  net  result  of  Mr.  Crookes'  researches  becomes  nothing  less 
than  the  discovery  of  a  new  law  of  nature  of  great  magnitude  and 
the  broadest  possible  generality,  viz. :  That  the  sun  and  all  other 
radiant  bodies,  that  is,  all  the  materials  of  the  universe,  exert  a 
mechanical  repulsive  force  in  addition  to  the  calorific,  luminous, 
actinic  and  electrical  forces  with  which  they  have  hitherto  been 
credited." 

"According  to  the  doctrine  of  exchanges,  which  has  now  passed 
from  the  domain  of  theory  to  that  of  demonstrated  law,  all  bodies, 
whatever  be  their  temperature,  are  perpetually  radiating  heat  force, 
the  amount  of  which  varies,  ceteris  paribus,  with  their  temperature. 
We  now  add  to  this  generalization  that  all  bodies  are  similarly 
radiating  mechanical  force  and  suffering  corresponding  mechanical 
reaction." 

From  the  same  volume,  page  115 : 

"  Tf  heat  be  motion,  actual  motion  of  actual  matter,  mechanical 
force  must  be  exerted  to  produce  it." 

I  will  add  a  few  quotations  from  that  extremely 


ILLUSTRATIONS    OF    GRAVITATION.  Ill 

accurate   scholar    and   writer,    Prof.    Alfred    Daniels. 
kk  Daniels'  Physics,"  page  433  : 

"When  a  succession  of  waves  impinges  on  a  mass  of  ordinary 
matter,  the  effect  varies  according  to  the  nature  and  the  condition  of 
the  body  which  receives  their  shock;  if  it  be  an  ordinary  opaque 
mass,  that  mass  may  be  warmed,  wave  motion  being  transformed 
into  heat,  and  the  waves  which  have  impinged  upon  it  are  ex  post 
facto  called  a  beam  of  radiant  heat." 

That  is,  the  waves  of  heat  before  impact  were  waves 
of  mechanical  motion. 
Again,  page  343 : 

"But  while  ether  waves  are  in  course  of  traversing  the  ether, 
there  is  neither  heat,  light  nor  chemical  decomposition  —  merely 
wave  motion  and  transference  of  energy  by  wave  motion." 

It  is  only  by  impact  that  they  turn  to  light  and  heat, 
and  prior  to  this  impact  they  are  waves  of  energy  in  the 
form  of  mechanical  motion.  These  long  waves  of 
mechanical  motion,  slightly  tired  as  we  may  imagine  by 
their  long  journeys  through  space,  are  revived,  so  to 
speak,  by  their  impact  upon  the  sun  —  not  increased  in 
quantity,  but  broken  up  into  the  shorter  waves  that 
represent  intense  heat  and  light. 

If  these  quotations  are  reliable,  we  have  a  funda- 
mental principle  in  physics,  to  wit:  That  all  forms  of 
matter,  even  the  firm  foundations  of  the  everlasting 
hills,  are  in  a  constant  state  of  insensible  tremor ;  that 
this  tremor  is  not  confined  to  the  subject  of  it,  but  is 
sent  all  abroad  through  the  universal  ether  to  the  very 
confines  of  creation.  But  it  is  not  to  the  feeble  vibra- 
tions of  mechanical  force  sent  forth  by  the  cold  bodies 
of  space  that  I  would  mainly  look  for  the  mighty  ener- 
gies that  kindle  the  solar  fires  throughout  the  heavens, 
and  by  their  refluent  waves  of  gravitation  gather  all  the 
planetary  hosts  into  family  circles  around  their  respec- 


112  GRAVITATION. 

tive  firesides.  The  suns  themselves  are  the  grand  foun- 
tains primarily  of  heat,  but  convertible  into  mechanical 
force  in  the  form  of  gravitation,  and  reconvertible  into 
heat  in  an  endless  cycle. 

It  is  now  well  settled  that  the  rays  of  intense  heat 
that  emanate  from  the  solar  bodies  immediately  com- 
mence a  process  of  degradation,  or  more  properly  of 
specialization  into  other  forms  of  energy.  Otherwise  the 
universe  would  now  be  a  universal  Tophet.  Having 
almost  infinite  spaces  to  traverse,  these  radiations  have 
ample  time  and  space  in  which  to  complete  their 
metamorphoses.  It  is  not  at  all  strange,  therefore,  that 
the  radiations  from  the  fixed  stars  should  reach  both  our 
earth  and  sun  mainly  in  the  form  of  mechanical  motion 
and  other  forms  of  energy.  Our  earth  does  not  possess 
the  machinery,  so  to  speak,  for  the  re-conversion  of 
these  returning  radiations  into  heat,  but  the  sun  is  an 
engine  exactly  adapted  to  this  work. 

The  great  argument  that  inclines  the  writer  to  believe 
that  there  are  waves  of  mechanical  force  coming  from 
the  directions  of  every  point  in  the  starry  concave, 
sweeping  athwart  the  earth's  orbit  at  every  point ;  and 
that,  being  shielded  by  the  sun  from  the  waves  coming 
from  the  opposite  direction,  the  great  earth  is  pushed 
toward  the  sun  and  the  greater  sun  toward  the  earth  — 
the  great  argument,  I  say,  is  the  great  fact  itself  that 
the  earth  is  actually  being  borne  in  toward  the  sun 
exactly  as  if  acted  upon  by  such  a  force. 

If  we  should  see  at  a  distance  a  train  of  cars  speeding 
across  the  landscape,  as  if  impelled  by  a  locomotive  with 
steam  up,  we  should  inevitably  infer  that  such  was  the 
fact.  If  we  could,  at  a  safe  distance,  behold  buildings, 
trees,  and  the  very  ground  itself  torn  up  and  tossed 


ILLUSTRATIONS    OF    GRAVITATION.  113 

about  exactly  as  if  a  cyclone  were  sweeping  over  the 
scene,  we  should  certainly  infer  that  such  was  the  case. 
If  we  should  see  even  a  leaf  fluttering  as  if  shaken  by 
the  wind,  we  should  certainly  infer  that  the  wind  was 
there. 

So,  if  we  behold  a  sublime  phenomenon  in  the  heav- 
ens that  can  be  accounted  for  by  just  such  a  force  as 
I  have  described;  if  such  a  force  is  known  to  exist, 
adequate  to  the  effect,  and  if  no  other  cause  is  known, 
is  not  the  mind  acting  normally  and  rationally  in  ac- 
cepting it  ? 

This  argument  can  be  appreciated  by  all  for  what  it 
is  worth.     But  other  arguments  and  illustrations  bear- 
ing on  the  subject  are  numerous,  to  a  few  of  which  we 
will  now  invite  the  reader's  attention. 
8 


CHAPTER  III. 

GRAVITATION   NOT  A  POSITIVE   FORCE   EXERTED   BY 

THE  SUN. 

All-intellectual  eye !     Our  solar  round 

First  gazing  through,  he,*  by  the  blended  power 

Of  gravitation  and  projection,  saw 

The  whole  in  silent  harmony  revolve. 

— THOMSON. 

IF  gravitation  is  a  positive  force  emanating  from  the 
sun,  it  must  be,  like  light  and  heat,  a  force  radi- 
ating equally  in  all  directions,  as  well  where  there  is  an 
absence  as  where  there  is  the  presence  of  bodies  to  be 
acted  upon.  If  this  be  so,  there  must  be  a  correspond- 
ing lowering  of  the  temperature  of  the  sun  to  supply 
the  force  of  gravitation,  in  addition  to  the  cooling  effect 
of  the  radiations  of  light  and  heat. 

According  to  such  a  theory,  we  have  two  outflowing 
streams,  each  co-extensive  with  the  sun's  surface,  each 
filling  all  space  to  an  infinite  distance,  but  with  no 
inflowing  stream  to  reimburse  these  almost  infinite  ex- 
penditures. 

According  to  the  theory  here  advocated,  the  receipts 
and  expenditures  always  balance  each  other  to  a  frac- 
tion, not  only  at  the  sun,  but  on  the  earth  and  through- 
out creation. 

There  is  no  running  down  and  no  running  up,  no 
increase  and  no  decrease  in  the  energies  of  nature,  but 

*  Newton. 
J14 


STILL    ANOTHER    VIEW.  115 

one  grand,  solemn,  ever  onward  march,  keeping  step  to 
the  "music  of  the  spheres." 

STILL  ANOTHER  VIEW. 

We  may  properly,  for  the  purpose  of  illustration, 
figure  the  earth  as  composed  of  only  one  molecule,  and 
the  sun  of  330,000,  that  being  about  the  ratio  of  their 
masses.  Then  the  earth,  composed  of  one  molecule,  will 
intercept  one  unit  of  force  from  each  of  the  330,000 
molecules  of  the  sun,  but  in  doing  so  will  receive  on  the 
side  turned  from  the  sun  330,000  blows  or  impulses, 
which  will  correspondingly  accelerate  its  motion  toward 
the  sun.  Hence  the  earth  falls  toward  the  sun  through 
330,000  times  the  distance  through  which  the  sun  falls 
toward  the  earth.  But  each  one  of  the  330,000  mole- 
cules in  the  sun  can  only  intercept  one  unit  of  force 
from  the  earth,  because  by  the  supposition  there  is  only 
one  molecule  in  the  earth  to  operate  upon.  Hence  the 
earth  and  sun  are  in  a  position  to  exert  each  on  the 
other  exactly  the  same  amount  of  negative  force ;  and 
on  the  supposition  that  all  space  is  filled  with  cosmic 
waves  of  force  flying  in  all  directions,  they  cannot  avoid 
intercepting  them  according  to  the  law  here  laid  down, 
which  is  identical  with  the  law  of  universal  gravitation. 

As  all  roads  in  Italy  lead  to  Rome,  so  every  view  we 
can  take  of  gravitation  leads  directly  to  the  conclusion 
that  it  is  a  force  present  to  the  earth  at  every  point, 
passing  athwart  her  orbit,  coming  from  the  depths  of 
space  and  impelling  the  earth  toward  the  sun,  according 
to  the  universal  law  that  all  bodies  move  in  the  direc- 
tion of  the  least  resistance,  the  resistance  being  least  in 
the  direction  toward  the  sun,  because  the  sun  intercepts 
a  portion  of  the  cosmic  waves  from  the  opposite  direc- 


116  GRAVITATION. 

tion.  Why  the  sun  sends  out  undulations  of  light  and 
heat  only,  omitting  mechanical  force,  we  have  endeav- 
ored to  explain  in  another  place.  But  even  these  undu- 
lations of  light  and  heat,  after  wandering  for  unknown 
periods  in  the  wilderness  of  space  and  becoming  shorn 
of  their  amplitude,  may  act  as  the  centripetal  force  to 
the  planets  of  some  far  distant  brother  sun. 


CHAPTER  IV. 

SUMMARY    OF    ARGUMENTS.  —  ASTRONOMICAL    ARGU- 
MENT. 

The  rich  abundance  of  the  accurate  observations  furnished  by 
Tycho  Bralie,  himself  a  zealous  opponent  of  the  Copemican  system, 
laid  the  foundation  for  the  discovery  of  those  eternal  laws  of  the 
planetary  movements  which  prepared  imperishable  renown  for  the 
name  of  Kepler,  and  which,  interpreted  by  Newton,  and  proved 
theoretically  and  necessarily  true,  have  been  transferred  into  the 
bright  and  glorious  domain  of  thought,  as  the  intellectual  recognition 
of  nature. —  HUMBOLDT'S  "  COSMOS." 

THE  names  of  Copernicus,  Tycho  Bralie,  Kepler  and 
Newton  will  each  receive  an  added  lustre  if  it  shall 
be  found  that  the  sublime  conceptions  of  the  first,  the 
patient  observations  of  the  second,  the  discovery  of 
the  true  laws  of  planetary  motion  by  the  third,  and  the 
interpretation  by  the  fourth  of  all  these  conceptions, 
observations  and  laws  by  one  word  —  gravitation  — 
have  led  inevitably  to  naming  the  causa  causans  of 
gravitation  itself. 

SUMMARY  OF  ARGUMENTS. 

1.  Gravitation,  like  light  and  heat,  acts  upon  bodies 
widely  separated  from  each  other,  and  connected  by  no 
medium  except  the  intervening  ether. 

Gravitation  must  act  through  this  ether,  or  through 
nothing,  which  is  inconceivable.  Heat  is  not  matter, 
but  a  state  of  matter.  But  mechanical  force,  of  which 
gravitation  is  a  conspicuous  example,  is  as  much  a  state 
of  matter  as  heat,  and  just  as  necessarily  involves  the 

117 


118  GRAVITATION. 

existence  of  a  material  medium  through  which  it  acts. 
Can  we  affirm  the  existence  of  a  state  of  matter,  and  at 
the  same  time  deny  the  existence  of  the  matter  itself 
constituting  this  medium  ? 

2.  If  gravitation  is  propagated  through  this  ether,  it 
must  be  by  waves  or  undulations.     The  molecules  of 
matter  do  not  pass  from  the  sender  to  the  receiver,  but 
only  a  state  or  condition  of  matter ;  that  is,  a  condition 
of  vibration  in  which  the  molecules  actually  move  only 
to  an  infinitesimal  extent. 

3.  The  undulations  by  which  the  force  of  gravita- 
tion is  propagated  must,  like  all  vibrations,  proceed 
from  senders  to  receivers,  and  their  energy  must  of 
necessity  be  exerted  in  the  direction  from  the  sender  to 
the  receiver. 

4.  We  know  that  waves  of  energy  do  actually  pro- 
ceed from  the  senders  and  occupy  appreciable  time  in 
reaching  the  receivers  —  light  travelling  at  the  rate  of 
eleven  and  a  half  million  miles  per  minute  —  so  that  the 
energy  exists  at  the  sender  before  it  reaches  the  receiver. 

5.  This  force  or  a  preponderance  of  this  force  of 
gravitation  must  be  delivered  on  the  side  of  the  earth 
opposite  the  sun,  impelling  the  earth  toward  the  sun,  and 
must  come  from  the  direction  of  the  outlying  starry 
concave;   and   as   every  wave   must   have  a   material 
sender,  the  senders  of  these  waves  of  force  can  be  no 
other  than  the  starry  hosts  that  stud  the  firmament  of 
heaven. 

6.  We  will  here  introduce  a  figure  showing  how  a 
ball  is  forced  to  the  earth  on  the  principle  here  laid 
down. 

Let  E  be  the  earth,  and  the  little  black  object  near 
it  a  cannon  ball  let  fall. 


SUMMARY    OF    ARGUMENTS. 


119 


The  waves  of  force  are  darting  in  all  directions,  and 
impinging  on  every  side  of  the  ball  equally,  except 
where  intercepted  by  the  earth. 

Let  the  circle  a  1)  c  d  represent  the  hollow  sphere 
of  the  heavens  relatively  to  the  ball.  It  is  obvious  that 
all  the  rays  of  force  from  the  hemisphere  a  b  c  will 
6 


tend  by  direct  or  resultant  action  to  push  the  ball  toward 
the  earth ;  also,  that  all  the  rays  from  the  hemisphere 
a  d  c,  except  those  intercepted  by  the  earth,  will,  in 
like  manner,  tend  to  push  it  in  the  opposite  direction. 

These   intercepted   waves,   if  unintercepted,  would 
neutralize  an  equal  number  from  opposite  directions; 


120 


GRAVITATION. 


and  the  bail,  being  acted  on  equally  in  all  directions, 
would  remain  stationary.  But  a  part  of  these  neutral- 
izing waves  being  intercepted,  the  ball  is  left  unsup- 
ported to  that  extent ;  the  props  are  knocked  out,  and 
the  ball  is  impelled  by  the  waves  of  mechanical  force 
from  the  opposite  side  to  fall  to  the  ground. 

It  will  be  observed  that  only  the  rays  from  f  to  g  are 
intercepted  from  the  ball  in  Figure  4.  If  we  repeat 
the  figure,  placing  the  ball  much  nearer  to  the  earth,  it 

a 


will  be  seen  that  many  more  rays  between  f  and  g  will 
be  intercepted,  and  consequently  the  force  of  gravita- 
tion on  the  ball  in  this  position  will  be  greatly  increased. 


SUMMARY    OF    ARGUMENTS.  121 

The  mechanical  force  intercepted  by  the  sun  from 
reaching  the  earth  and  by  the  earth  from  reaching  the 
sun  are  precisely  equal,  being  in  both  cases  equal  to  the 
number  of  molecules  in  the  sun  multiplied  by  the  num- 
ber in  the  earth,  divided  by  the  square  of  the  number  of 
feet,  miles  or  millions  of  miles,  measuring  the  distance 
between  the  centres  of  the  two  bodies. 

Otherwise  expressed  ;  each  and  every  molecule  in  the 
earth  intercepts  one  unit  of  force  from  each  and  every 
molecule  in  the  sun,  and  vice  versa.  This  produces 
equality  of  gravitative  force  in  both  directions  through 
equality  of  inertia  in  all  the  particles.  Is  there  any 
other  theory  consistent  with  equality  of  gravitation  be- 
tween great  and  small  bodies,  and  also  with  equivalence 
of  force,  positive  or  negative,  in  the  particles  by  or 
through  which  gravitation  is  effected  ? 

In  the  preceding  figures  large  and  small  masses  are 
necessarily  represented  by  large  and  small  volumes  re- 
spectively, but  gravitation  is  proportioned  to  mass,  of 
course,  and  not  to  volume. 

But  the  intercepted  waves,  though  measuring  the 
force  of  gravitation,  do  not  constitute  that  force.  They 
are  only  the  negative  counterpart  of  the  positive  and 
effective  waves. 

If,  however,  the  ball  had  a  tangential  motion,  equal 
to  about  300  miles  per  minute,  it  would  not  reach  the 
ground  at  all,  but  would  revolve  like  a  little  satellite 
around  the  earth  forever,  if  unimpeded  by  friction. 
It  would  not  stop  falling,  however,  but  its  tangen- 
tial motion  would  furnish  it  from  moment  to  moment 
with  new  space  through  which  to  continue  its  never- 
ending  fall. 

Precisely  analogous  is  the  condition  of  the  earth  and 


122  GRAVITATION. 

other  planets  in  respect  to  the  sun,  and  the  satellites  in 
respect  to  their  primaries.  The  earth  is  forever  fall- 
ing toward  the  sun,  but  the  tangential  motion  of  the 
earth  at  the  same  time  carries  it  to  a  distance  from  the 
sun  precisely  equal  to  the  distance  through  which  it  falls 
in  a  given  time,  so  that  the  earth  preserves  its  mean 
distance  from  the  sun  unchanged  forever. 

This  force  of  gravitation,  in  connection  with  tangen- 
tial motion,  is  doing  its  work  every  moment.  On  this 
first  day  of  May,  at  8  A.M.,  the  earth  is  moving  through 
the  diagonal  of  a  parallelogram  representing  the  two 
forces  in  obedience  to  which  it  moves.  No,  we  are 
mistaken;  it  has  left  this  diagonal  and  entered  upon 
another — mistaken  again  —  it  has  left  this  also  and 
adopted  a  third  diagonal  of  a  third  parallelogram. 
While  we  have  been  writing  and  you  have  been  reading 
these  two  or  three  lines,  the  earth  has  entered  upon  and 
abandoned  thousands,  yea  an  infinite  number  of  these 
diagonals.  Expressed  in  the  language  of  the  geometri- 
cians, the  path  of  the  earth  in  its  orbit  is  a  series  of  infi- 
nitely short  diagonals  of  infinitely  small  parallelograms. 

7.  Though  Newton,  the  prince  of  philosophers,  for 
convenience,  applied  the  word  "attraction"  to  gravita- 
tion, he  expressly,  in  language  formal  and  emphatic, 
pronounced  the  idea  too  absurd  to  be  entertained  by 
any  sound  mind,  as  appears  by  the  following  extract 
from  a  letter  to  Bentley,  quoted  approvingly  by  Fara- 
day, thus: 

"  That  gravity  should  be  innate,  inherent  and  essential  to  matter, 
so  that  one  body  may  act  on  another  at  a  distance  through  a  vacuum 
without  the  mediation  of  anything  else,  by  and  through  which  their 
action  and  force  may  be  conveyed  from  one  to  another,  is  to  me  so 
great  an  absurdity  that  I  believe  no  man  who  has,  in  philosophical 
matters,  a  competent  faculty  of  thinking,  can  ever  fall  into  it. 


AN    ASTRONOMICAL    ARGUMENT.  123 

Gravity  must  be  caused  by  an  agent  acting  constantly  according  to 
certain  laws." 

This  renders  it  certain,  so  far  as  the  authority  of  a 
great  name  can  go,  that  gravity  is  not  and  can  not  be 
the  action  of  one  body  at  a  distance  on  another  without 
an  intervening  medium.  This  medium  we  now  know  can 
be  none  other  than  the  universal  ether.  Newton  says : 
"  Gravity  must  be  caused  by  an  agent  acting  constantly 
according  to  certain  laws/'  What  can  this  agent  or 
force  be  but  the  known  mechanical  vibrations  with 
which  every  form  of  matter  is  endowed?  And  as  to 
the  "certain  laws,"  what  can  they  be  except  the  laws 
by  which  all  kinds  of  matter,  in  their  capacity  of  send- 
ers, transmit  through  the  all-embracing  ether  these  vibra- 
tions of  force  to  the  bodies  lying  in  their  paths  as 
receivers  f 

There  is  no  escape  from  the  conclusion  that  Newton 
conceived  of  the  force  of  gravity,  not  vaguely,  but 
sharply  and  certainly,  according  to  its  true  nature,  so 
far  as  he  was  able  or  chose  to  pursue  the  subject,  and  I 
believe  every  candid  reader  will  admit  that  his  views 
harmonize  perfectly  with  those  here  advanced. 

AN  ASTRONOMICAL  ARGUMENT. 

We  will  here  introduce  an  argument  in  favor  of 
our  view  of  the  nature  of  gravitation,  which,  if  fully 
presented  and  properly  appreciated,  amounts  to  a  dem- 
onstration. It  is  well  known  by  all  astronomers  that 
gravitation  acts  instantaneously  between  the  earth  and 
sun.  If  gravitation  consisted  in  a  line  of  force  sent  out 
by  the  sun,  directed  toward  the  earth  and  travelling  in 
a  straight  line  with  the  velocity  of  light,  it  would  arrive, 
not  at  the  earth,  but  at  the  place  occupied  by  the  earth 


124  GRAVITATION. 

when  this  line  of  force  left  the  sun,  eight  minutes  too 
late.  The  same  would  be  the  case  with  every  succeed- 
ing line  of  force  sent  out  by  the  sun.  On  the  hypoth- 
esis that  gravitation  is  a  force  exerted  by  the  sun,  which 
we  deny,  one  of  two  things  must  be  true.  Either  the 
sun  is  capable  of  sending  out  lines  of  force  instantane- 
ously through  some  medium  to  the  distance  of  ninety- 
two  and  a  half  million  miles,  or  else  he  is  constantly 
sending  out  such  lines  in  all  directions,  the  same  as  he 
is  sending  out  rays  of  light  and  heat.  In  regard  to  the 
first  supposition,  it  is  sufficient  to  say  that  our  ether  is 
not  known  to  possess,  the  capacity  of  transmitting  any 
undulations  faster  than  eleven  and  a  half  million  miles 
per  minute,  and  no  one  has  yet  claimed  or  even  sug- 
gested the  existence  of  any  other  kind  of  ether.  Take 
the  other  hypothesis,  that  the  sun  is  constantly  sending 
forth  the  force  of  gravitation  in  all  directions,  so  that  it 
is  always  present  at  any  and  every  point  in  its  orbit  at 
which  the  earth  may  be  found,  then  here  is  as  great  an 
expenditure  of  real  force  by  the  sun  for  the  purposes  of 
gravitation  as  for  light  and  heat.  Now  the  physicists 
have  been  sorely  puzzled,  for  many  years  past,  to  know 
how  the  sun  keeps  up  his  supply  of  light  and  heat  alone. 
If  this  additional  burden  is  laid  upon  him,  will  he  not 
surely  break  down  under  the  accumulated  load  ?  But 
seriously,  every  expenditure  of  force  producing  motion 
or  doing  work  by  any  inanimate  object  as  surely  involves 
exhaustion  as  does  the  expenditure  of  the  forces  of  the 
human  system.  All  kinetic  energy,  as  we  have  often 
said,  is  matter  in  motion. 

If  a  heated  body  gives  off  heat  it  is  thereby  cooled. 
If  a  moving  body  communicates  its  motion  to  another 
body,  it  is  thereby  brought  to  a  state  of  rest.  There  is 


AN    ASTRONOMICAL    ARGUMENT.  125 

no  exception  to  this  inexorable  law  of  nature.  If  the 
sun  exerts  the  force  of  gravitation  in  all  conceivable 
directions,  whether  there  be  worlds  to  operate  upon  or 
not,  as  he  sends  forth  light  and  heat,  then  the  sun  is  the 
subject  of  two  appalling  and  irreparable  wastes,  unless 
he  is  reimbursed  for  these  expenditures  from  sources 
outside  of  his  own  mass. 

The  argument  is  short,  sharp  and  apparently  conclu- 
sive. The  action  of  gravitation  between  the  sun  and 
the  earth,  as  every  astronomer  knows,  is  instantaneous. 
Light  travelling  at  the  rate  of  eleven  and  a  half  million 
miles  per  minute  requires  eight  minutes  to  reach  the 
earth  from  the  sun.  Who  will  believe  that  gravitation 
can  emanate  from  the  same  body,  travel  the  same  road 
by  the  same  medium,  and  accomplish  the  journey  in  no 
time  f  But,  according  to  the  theory  of  incoming  waves, 
they  are  always  present  at  every  point  in  the  earth's 
orbit,  and  take  effect  instantly,  which  is  just  what 
astronomy  demands. 

Not  only  is  the  positive  force  present  and  ready  to 
act,  but  the  negative  is  present  also  by  virtue  of  the 
absence,  to  a  variable  extent,  of  a  neutralizing  positive 
force  from  the  opposite  direction.  The  positive  force 
is  absolutely  unvarying ;  the  negative  varies  according 
to  the  law  of  the  inverse  squares,  producing  an  ap- 
parent corresponding  variation  of  the  positive  force. 


CHAPTEE  Y. 

GRAVITATION  — ITS  RELATION   TO  CORRELATION  AND 
CONSERVATION  OF  ENERGY. 

Oninia  mutantur,  nihil  interit. — OVID. 

"TTTHEN  electricity  passes  along  a  slender  wire  or 
VV  other  obstructive  medium,  heat  is  generated; 
so  also,  when  heat  is  applied  to  the  point  of  union 
between  a  bar  of  zinc  and  another  of  copper,  elec- 
tricity is  generated.  And  generally,  whenever  a  trans- 
formation of  energy  from  one  kind  to  another  takes 
place,  the  doctrine  of  the  correlation  of  forces  re- 
ceives a  fresh  illustration.  Every  new  exhibition  of 
energy  as  heat,  electricity,  mechanical  motion,  etc.,  is 
invariably  preceded  and  sooner  or  later  followed  by 
some  other  related  form,  each  sustaining  to  the  other  in 
turn  the  relation  of  cause  and  effect.  This  wonderful 
relation  has  been  expressed  by  the  term  "  correlation  of 
forces." 

These  exhibitions  of  force  do  not,  by  any  means, 
always  resemble  each  other ;  on  the  contrary,  they  are 
often  quite  diverse.  They  are  all  held  to  be  different, 
probably  widely  different,  kinds  of  molecular  motion. 
They  all  resemble  each  other,  however,  in  this,  that 
when  one  form  ceases  another  begins,  and  vice  versa, 
And  yet  gravitation  between  the  heavenly  bodies,  one 
of  the  most  wonderful  exhibitions  of  energy  in  nature, 
is  left  wholly  uncorrelated  with  preceding  or  succeeding 
exhibitions  of  energy.  This  cannot  possibly  be  so. 

J26 


CORRELATION    AND    CONSERVATION    OF    ENERGY.      127 

The  theory  here  advocated  is  the  only  one  broached,  so 
far  as  I  know,  which  correlates  or  brings  the  force  of 
gravitation  into  relation  with  the  other  forces  of  nature. 
By  this  theory  it  is  correlated  on  one  side  with  the 
obscure  or  mechanical  rays  or  vibrations  with  which  the 
universal  ether  is  replete,  and  on  the  other  with  the 
reproduction  of  the  heat  of  all  the  suns,  and  through 
them  of  all  the  worlds  that  inhabit  space. 

Gravitation  drives  our  mills,  grinds  our  corn,  weaves 
our  garments,  runs  our  clocks,  and  in  many  other 
ways  renders  itself  useful  in  mundane  affairs.  It  con- 
stitutes the  sum  total  of  what  is  called  the  energy  due 
to  position.  It  is  readily  convertible  into  heat,  and 
passes  thence  through  all  the  forms  of  dynamic  action. 
In  all  these  relations  it  is  freely  admitted  into  full  com- 
munion and  good  and  regular  standing  in  the  fellowship 
of  all  the  forces.  But  the  performances  of  gravitation 
on  the  earth  exhibit  but  an  exceedingly  small  arc  of  the 
grand  circle  through  which  it  moves.  The  heavens 
declare  the  length  and  breadth,  the  height  and  depth  of 
this  all-pervading  force.  Is  it  the  proper  treatment,  I 
ask,  to  excommunicate  this  member  of  the  family  of  the 
forces  the  moment  it  leaves  the  earth?  As  generally 
accepted,  it  is  uncorrelated,  because  it  is  not  made  the 
successor  of  any  previous  exhibition  of  force,  nor  the 
predecessor  of  any  to  follow.  It  is  represented  as 
isolated  without  cause  and  without  effect.  It  is  uncon- 
served,  because  in  the  case  of  our  earth,  e.g.,  it  is  ex- 
erted anew  at  every  point  of  the  earth's  orbit  and  then 
vanishes  forever.  Can  these  things  be?  If  so,  the 
exceptions  to  the  universal  laws  of  correlation  and  con- 
servation are  immeasurably  greater  than  the  cases  cov- 
ered by  these  laws.  It  is  too  plain  for  argument  that 


128  GRAVITATION. 

we  must  give  up  the  laws  of  correlation  and  conserva- 
tion or  else  so  frame  them  as  to  include  both  heat  and 
gravitation.  I  may  as  well  remark  here  that  these  two, 
heat  and  mechanical  force  or  gravitation,  are  espe- 
cially the  correlatives  of  each  other.  Where  one  is 
found  the  other  is  not  far  to  seek. 

What  is  necessary  to  bring  gravitation  under  the  law 
of  correlation  in  the  heavens  ?  All  are  familiar  with  its 
correlations  on  the  earth.  The  correlation  of  forces,  in 
its  broadest  sense,  may  refer  to  a  force  as  leaving  one 
body  and  acting  on  another,  or  to  a  change  of  form,  as 
from  mechanical  motion  to  heat,  but  in  all  cases  it 
involves  the  fact  of  transmigration.  To  bring  gravita- 
tion under  this  law,  therefore,  absolutely  requires  that 
it  should  have  a  whence  and  a  whither  —  a  source  and  a 
destination.  It  cannot  emerge  from  non-existence  nor 
disappear  in  annihilation. 

What  is  necessary  for  its  conservation  ?  It  must  be 
shown  that  while  gravitation  is  doing  its  work  of 
impelling  the  earth  toward  the  sun,  it  must  draw  upon 
some  other  source  of  energy.  This  can  only  be  done  by 
lowering  the  temperature  of  some  body  or  bodies 
other  than  the  earth  and  sun  upon  which  the  force  of 
gravity  is  exerted,  or  by  depriving  these  other  bodies  of 
their  mechanical  motion,  and  thus  bringing  them  to 
rest.  It  must  also  be  shown  that,  in  performing  its 
work,  it  must  communicate  its  energy  to  the  bodies 
upon  which  this  work  is  performed,  which  can  only  be 
done  by  overcoming  the  inertia  and  changing  their 
direction,  or  by  elevating  their  temperature ;  in  fact,  it 
does  both  to  a  certain  extent.  It  changes  the  path  of 
the  earth  from  its  tangential  motion  in  a  straight  line  to 
a  falling  motion  toward  the  sun;  and  at  the  sun,  by 


CORRELATION    AND    CONSERVATION    OF    ENERGY.      129 

the  stoppage  of  its  mechanical  motion,  it  changes  to  its 
correlative  heat.  It  would  be  possible  to  follow  this 
force  in  its  further  transmigrations  and  changes,  but  it  is 
unnecessary.  It  must  always  be  borne  in  mind,  as  I  have 
elsewhere  shown,  that  the  amount  of  this  force  actually 
expended  in  curving  the  orbits  of  the  planets  is  almost 
infinitesimal,  compared  with  the  whole  amount.  The 
whole  field  of  the  heavens  is  as  full  of  this  force  as  the 
comparatively  small  space  occupied  by  the  earth  and 
planets. 

This  is  the  place  to  answer  the  question,  Whence 
comes  the  force  of  gravitation  according  to  the  theory 
here  advocated  ?  I  reply,  From  every  particle  of  mat- 
ter, hot  or  cold,  in  the  universe,  in  a  state  of  propulsive 
vibration,  but,  of  course,  mainly  from  the  grand  solar 
bodies,  which  send  forth  their  emanations  in  the  form 
of  heat,  and  receive  them  again  in  the  form  of  its  cor- 
relative, mechanical  motion,  again  to  be  changed  into 
heat  and  so  on  forever.  All  of  these  vibrating  bodies 
of  course  exhaust  themselves  in  sending  forth  these 
vibrations,  and  require  replenishment  from  the  same 
universal  ether  in  an  endless  cycle.  Every  body,  large 
and  small,  hot  or  cold,  yea,  every  molecule,  acts  both  as 
a  .sender  and  receiver  of  vibrations,  and  therefore  pre- 
serves its  average  condition  as  to  energy  from  age  to 
age.  Especially  is  this  the  case  with  the  sun,  preserv- 
ing an  average  uniformity  of  heat,  receiving  and  dis- 
pensing the  same  amount,  and  so  remaining  unchanged. 

It  is  simply  a  physical  impossibility  for  the  sun  to 
exert  any  force  per  se,  much  less  a  force  filling  the 
whole  heavens  and  pervading  all  space  entirely  uncor- 
related  with  any  preceding  form  of  kinetic  energy.  Not 
a  physical  motion,  great  or  small,  can  possibly  exist,  ex- 
9 


130  GKAVITATION. 

cept  as  the  successor  of  a  prior  motion.  As  well  might 
a  child  be  born  without  father  or  mother.  As  well 
might  a  river  spring  from  the  Desert  of  Sahara  without 
connection  with  any  other  fountain  or  source  of  water 
or  the  elements  of  which  it  is  composed.  The  force  of 
gravitation  is  only  a  link  in  a  chain.  It  cannot  be  dis- 
connected from  the  preceding  links  nor  from  those 
which  follow.  It  must  also,  to  the  last  iota,  be  con- 
served as  well  as  correlated.  A  theory  that  uses  gravi- 
tation only  to  hoop  the  heavens  together,  and  then  dis- 
misses it,  never  to  reappear  in  the  grand  economies  of 
nature,  is  false  on  its  face.  Nature  is  as  parsimonious  as 
she  is  prodigal.  But  her  parsimony  always  follows  in 
the  wake  of  her  prodigality,  and  sees  that  nothing  is 
lost. 


CHAPTER  VI. 

ACTION  ATA  DISTANCE— PROPULSION  VS.  TRACTION. 

So  reigns  the  Newtonian  hypothesis  of  gravity.  It  is  everywhere 
supreme  —  in  the  books,  in  the  schools,  in  the  innermost  convictions 
of  all  intelligent  men.  —  PATER  MUNDI. 

THIS  oft  mooted  question  can  be  freed  from  much 
of  its  obscurity,  if  we  fix  clearly  in  our  minds  what 
kind  of  action  is  meant. 

It  is  not  mental  nor  supernatural  action  that  is  in- 
tended, but  purely  physical  action,  or  the  action  of  mat- 
ter on  matter.  The  mere  statement  of  the  question  an- 
swers it.  It  is  the  action  of  matter  on,  not  at,  other 
matter. 

If  the  actor  and  actee  be  in  contact,  the  action  is 
immediate.  If  not  in  contact,  the  action  must  be  inter- 
mediate, that  is  through  a  medium.  Action  at  a  dis- 
tance, without  an  intervening  medium,  is  inconceivable. 

But  aside  from  its  a  priori  impossibility,  actio  in 
distans  has  been  disproved  empirically  to  the  fullest 
satisfaction  of  every  person  and  even  of  every  brute 
that  ever  lived.  A  cow  may  attempt  to  scale  an  im- 
passable barrier  to  reach  coveted  food  or  drink ;  but  no 
sane  cow  will  stand  still,  with  no  barrier  between  her 
and  the  object  of  her  desires,  and  attempt  to  eat  or 
drink  at  a  distance. 

I  am  persuaded  that  the  idea  of  physical  action  at  a 
distance,  except  as  a  matter  of  curious  metaphysical 

131 


132  GRAVITATION. 

speculation,  would  never  have  been  seriously  entertained 
except  for  the  necessity  of  accounting  in  some  way  for 
the  action  of  gravitation. 

The  proof  of  the  existence  of  the  ether  rests  wholly 
upon  the  impossibility  of  action  at  a  distance.  If  this 
latter  were  possible,  then  the  waves  of  light  and  heat 
might  travel  through  vacuo  as  easily  as  the  impulses 
of  gravitation  have  been  supposed  to  do.  If  light 
and  heat  require  a  medium,  so  does  gravitation.  Can 
anything  be  more  absolutely  and  undeniably  true  ?  If 
gravitation  necessarily  involves  the  existence  of  a  mate- 
rial medium  between  the  sun  and  the  planets,  it  must 
be  something  which  fills  all  space,  for  gravitation  is 
more  than  Briarean  in  the  number  of  its  arms  and  the 
directions  of  its  action. 

But  the  ether  does  not  originate;  it  only  transmits 
vibrations  of  various  kinds.  These  vibrations  proceed 
only  from  ordinary  matter,  and  the  kind  of  vibrations 
depends  wholly  upon  the  kind  and  condition  of  the 
matter  from  which  they  emanate. 

Thus  every  view  we  can  possibly  take  of  gravitation 
comes  in  the  end  to  the  same  result;  viz.:  that  it  is  a 
mechanical  force  of  cosmic  origin,  emanating  from  all 
forms  of  matter,  ether  only  excepted,  propagated  in 
straight  lines  by  undulations  of  this  ether ;  and  as  all 
celestial  bodies,  acting  as  screens  to  each  other,  intercept 
these  undulations  from  each  other,  they  will  be  impelled 
toward  each  other  by  a  force  proportioned  to  the 
product  of  their  masses  divided  by  the  squares  of  their 
distances. 

PROPULSION  VS.  TRACTION. 

A  faint  glimmering  of  a  conception  that  propulsion 
and  traction  are  in  fact  one,  and  that  that  one  is  pro- 


PROPULSION   VS.    TRACTION.  133 

pnlsion,  is  often  present  to  many  minds.  The  clearer 
the  mind,  the  more  clearly  is  this  idea  developed. 
Newton,  speaking  of  force  in  its  broadest  and  most 
comprehensive  sense,  calls  it  " vis  a  tergo"  a  push  from 
behind.  We  will  confine  ourselves  to  the  consideration 
of  the  most  plausible  cases  of  traction  we  can  call  to 
mind,  and  see  whether  or  not  they  resolve  themselves 
into  propulsion. 

One  of  the  most  familiar  examples  of  traction  as 
well  as  one  of  the  grandest  exhibitions  of  physical  force 
with  which  we  are  familiar,  is  the  steam  engine  propel- 
ling a  train  of  cars.  It  is  true  that  the  engine  is  usually 
placed  before  the  train,  but  it  is  also  often  located  be- 
hind it,  in  which  case  the  action  is  clearly  of  the  nature 
of  a  push.  No  one  will  contend  for  a  moment  that 
there  is  the  slightest  difference  in  the  action  of  the  en- 
gine in  the  two  cases.  In  fact,  even  where  the  engine 
precedes  the  train,  a  hook,  link,  or  other  appliance  is 
inserted  behind  some  part  of  the  train  to  be  moved  and 
the  vis  a  teryo  is  manifest.  Again,  a  horse  is  said  to 
draw  the  cart,  but  he  exerts  all  his  strength  in  pushing 
with  his  shoulders  against  the  collar.  The  force  that 
expels  the  air  from  an  air  pump  is  the  expansive  action 
of  the  air ;  that  which  raises  water  in  a  suction  pump  is 
the  downward  pressure  of  the  atmosphere.  In  general, 
it  is  the  pushing  action  of  the  current  that  drives  the 
water  wheel.  Trees  are  pushed  over  by  the  wind. 
Ships  are  propelled  in  the  same  manner.  So  are  the 
waves  of  the  ocean.  In  fact  we  can  think  of  no  appli- 
cation of  mechanical  force  that  is  not  vis  a  tergo,  a  push 
from  behind.  Newton  was  right. 

It  may  be  asked  what  we  have   to   say  in  regard 


134  GRAVITATION. 

to  cohesive  attraction,  capillary  attraction,  and  mag- 
netic, electrical  and  chemical  attractions  ( 

All  these  forms  of  attraction,  so  called,  are  clearly 
differentiated  from  ordinary  mechanical  force,  which  is 
our  text  for  the  present.  As  yet  our  ignorance  is 
much  more  comprehensive  than  our  knowledge  in  re- 
gard to  the  modus  opcrandi  of  these  latter  forms  of 
energy.  But  those  who  have  bestowed  the  most  thought 
and  study  upon  them  regard  them  all  as  the  result  of 
vibratory  action  of  different  kinds,  proceeding  from 
matter  either  in  straight  or  curved  lines,  and  of  course 
outwardly  from  their  sources,  even  though  they  return 
like  the  boomerang  to  the  place  of  starting. 

Motion  is  communicated  to  matter  by  other  matter 
in  motion  and  not  otherwise.  But  it  is  entirely  aside 
from  the  design  of  this  work  to  enter  upon  any  discus- 
sion of  these  occult  forces. 

When  the  mind  has  once  conceived  the  nature  of 
physical  action,  which  can  only  arise  from  impact,  no 
argument  will  be  necessary  to  show  that  all  action  is 
necessarily  propulsive. 

Upon  so  plain  a  point  I  will  indulge  in  only  a  very 
few  quotations,  made  at  second  hand  from  Stallo's 
"  Modern  Physics,"  pages  52  to  57,  thus : 

"All  physical  action  therefore  is  by  impact;  action  at  a  dis- 
tance is  impossible;  there  are  in  nature  no  pulls,  but  only  thrusts; 
and  all  force  is  not  merely  (in  the  language  of  Newton)  vis  im- 
pressa,  but  vis  a  tergo." — Stallo. 

"There  is  no  other  kind  of  force  than  pressure  by  contact  of  one 
body  with  another." — Prof.  Challis. 

"All  physical  force  being  pressure,  there  must  be  a  medium  by 
which  the  pressure  is  exerted." — Idem. 

"  No  principle  will  ever  be  generally  received  that  stands  in  op- 
position to  the  old  adage,  '  A  thing  cannot  act  where  it  is  not,'  any 
more  than  it  would,  were  it  to  stand  in  opposition  to  that  other 


PROPULSION    VS.    TRACTION.  135 

adage,  'A  thing  cannot  act  before  it  is,  or  when  it  is  not.'" 
— James  Croll. 

"We  have  said  elsewhere  how  impossible  it  is  to  conceive 
what  is  called  an  attractive  force  in  the  strict  sense  of  the  term, 
that  is,  to  imagine  an  active  principle  having  its  seat  within  the 
molecules  and  acting  without  a  medium  through  an  absolute  void. 
This  amounts  to  an  admission  that  bodies  act  upon  each  other  at  a 
distance,  that  is,  where  they  are  not;  an  absurd  hypothesis,  equally 
absurd  in  the  case  of  enormous  and  in  that  of  very  small  dis- 
tances."— Father  Secchi. 

"  Gravity  cannot  act  except  by  the  interposition  of  ponderable 
matter." — F.  Mohr.  (The  word  "ponderable"  should  in  ray- 
opinion  be  omitted.) 

"  Forces  acting  through  void  space  are  in  themselves  incon- 
ceivable, nay  absurd,  and  have  become  familiar  concepts  among 
physicists  since  Newton's  time  from  a  misapprehension  of  his  doc- 
trine and  against  his  express  warning." — Du  Bois  Reymond. 

"  Of  course  the  assumption  of  action  at  a  distance  may  be  made 
to  account  for  anything;  but  it  is  impossible  (as  Newton  long  ago 
pointed  out  in  his  celebrated  letter  to  Bentley)  for  any  one  f  who 
has  in  philosophical  matters  a  competent  faculty  for  thinking'  for  a 
moment  to  admit  the  possibility  of  such  action." — Balfour  Stewart 
and  P.  G.  Tait. 

These  are  specimens  of  the  way  in  which  the  great- 
est minds,  Newton's  included,  have  asserted  the  im- 
possibility of  action  at  a  distance  without  an  inter- 
vening medium  and  the  consequent  impossibility  of 
matter  acting  on  matter  by  attraction. 

These  two  propositions,  to-wit:  first,  that  action  at  a 
distance  is  an  impossibility,  and,  second,  that  all  phys- 
ical action  is  propulsive  and  outward  from  the  bodies 
exercising  the  same,  seem  to  be  conclusive  of  the  truth 
of  the  doctrine  of  gravitation  here  advanced. 

To  confine  ourselves  for  the  present  to  the  earth 
as  an  illustration,  it  follows  from  the  above : 

1.  That  gravitation  is  a  propulsive  physical  force 
pushing,  not  pulling,  the  earth  toward  the  sun. 


136  GRAVITATION. 

2.  That  this  force  must  come  from  matter  outside 
of  the  earth's  orbit,  acting  by  impact,  either  direct  or 
through  an  intervening  medium. 

3.  But  there  are  no  outlying  material  bodies  nearer 
than  those  which  stud  the  firmament,  and  consequently 
they  must  act  through  a  medium. 

4.  There  is  but  one  known  medium  reaching  from 
the  earth  to  the  outlying  stars,  that  is,  the  ether. 

5.  This  medium  is  exactly  adapted  to  the  transmis- 
sion of  all  forms  of  energy,  acting  by  undulatory,  in- 
stead of  translatory,  motion. 

6.  As   the   celestial    bodies,   seen   and    unseen,  are 
probably  distributed  with  something  like  average  uni- 
formity through  space,  or  rather  extend  in  all  directions 
to  infinity,  the  rays  or  vibrations  of  mechanical  force 
will    necessarily  be  darting  in  all  possible  directions, 
and,  if  unintercepted,  would  impinge  on  all  sides  of 
the  earth  equally,  thus  neutralizing  each  other.     They 
would  perhaps  change  to  heat  from  arrested  motion, 
but  would  not,  if  unintercepted,  influence  the  earth's 
line  of  motion  in  the  least. 

7.  But  the  fact  that  these  rays  are  moving  in  all 
directions  in  straight  lines  makes  it  absolutely  certain 
that  a  portion  of  them  must  be  intercepted  from  the 
earth  by  the  sun  and  from  the  sun  by  the  earth,  form- 
ing between  these  bodies  a  line  of  least  resistance  in 
which   they   will   necessarily   tend   to   approach    each 
other. 

8.  As  the  earth  and  sun  are  permeated  through  and 
through  by  the  ether,  these  vibrations  find  no  difficulty 
in  reaching  every  molecule  in  both  bodies,  and  each 
molecule  in  one  body  intercepts  one  unit  of  force  from 
each  molecule  in  the  other ;  the  number  of  units  of  this 


PROPULSION    VS.    TRACTION.  137 

force  intercepted  from  the  sun  by  the  earth  is  precisely 
equal  to  the  number  of  molecules  in  the  earth  multi- 
plied by  the  number  in  the  sun,  and  vice  versa.  The 
earth  will  therefore  be  impelled  toward  the  sun  pre- 
cisely in  proportion  to  the  number  of  molecules  in  the 
sun,  multiplied  by  the  number  in  the  earth,  and  divided 
by  the  square  of  the  distance  separating  them;  and 
the  same  is  true  of  the  sun  and  of  all  bodies,  large  and 
small,  near  and  remote.  This  is  universal  gravitation 
by  means  of  propulsion,  not  attraction,  coextensive 
with  the  universe,  proceeding  from  individual  mole- 
cules, and  expending  itself  on  individual  molecules,  but 
in  the  aggregate  controlling  the  motions  of  every  sun, 
planet,  and  satellite  by  an  immutable  law. 


CHAPTER  VII. 

GRAVITATION  COMPARED  WITH   LIGHT    AND   HEAT. 

1  heard  the  trailing  garments  of  the  Night 

Sweep  through  her  marble  halls! 

I  saw  her  sable  skirts  all  fringed  with  light 

From  the  celestial  walls!  — LONGFELLOW. 

IT  has  occurred  to  the  writer  that  a  candid  and  care- 
ful comparison  between  the  combined  forces  of 
light  and  heat  on  the  one  hand,  and  gravitation  on  the 
other,  might  give  us  clearer  ideas  of  the  latter,  and 
perhaps,  if  properly  conducted,  be  decisive  as  to  the 
question  whether  gravitation  be  of  the  nature  of  a  pro- 
pulsion from  the  universal  starry  concave,  or  a  pull  by 
the  sun  alone,  upon  the  earth  and  other  planets. 

As  light  and  heat  are  closely  related  and  obey  sub- 
stantially the  same  laws,  it  will  be  sufficient  in  this 
comparison  to  name  either,  and  consider  one  name  as 
embracing  both. 

We  will  first  notice  a  few  points  in  which  light  and 
gravitation  resemble  each  other  sufficiently  to  make  it 
probable,  if  not  certain,  that  these  forces  stand  in  very 
close  relations. 

1.  Light  is  unquestionably  a  vibration  or  quivering 
of  the  universal  ether.  Gravitation  must  necessarily 
act  through  the  same  medium  from  sheer  want  of  any 
other,  and  just  as  necessarily  by  means  of  vibrations, 
as  the  ether  cannot  act  by  actual  transference  of  its 
substance. 

138 


GRAVITATION  COMPARED  WITH  LIGHT  AND  HEAT.     130 

2.  Li»;ht  diminishes  in  intensity  as  the  square  of  the 
distance   increases.      Gravitation   does   the   same,   but 
with  a  marked  distinction  to  be  hereafter  noticed. 

3.  Both  light  and  gravitation  are  regarded  by  all,  as 
emanating,  in  their  ineipiency,  from  ordinary  matter. 

4.  The  combined  force  of  light  and  heat,  and  the 
force  of  gravitation,  are  both  forms  of  energy  convert- 
ible in  turn  into  all  the  others. 

5.  These  two  forms  of  energy,  like  all  other  forms, 
are  subject  to  the  laws  of  conservation  and  correlation. 

Here  we  will  close  the  list  of  resemblances,  and  sub- 
mit that  they  are  amply  sufficient  to  justify  the  sus- 
picion, at  least,  of  a  closer  relationship  than  has  hither- 
to been  accorded  them. 

We  will  now  turn  our  attention  to  the  points  in 
which  they  differ,  and  the  conclusion  to  which  they 
point. 

1.  We  are  all  familiar  with  the  effects  produced  by 
the  rays  of  light  and  heat;  while  gravitation  operates 
with  exactly  the  same  force  and  certainty  amid  the  rigors 
of  the  poles  as  in  the  fervid  heat  at  the  equator.    Until 
the  waves  of  gravitation  are  metamorphosed  we  may 
be  pardoned  in  calling  them  cold  waves  in  distinction 
from  those  of  light  and  heat. 

2.  As  before  intimated,  there  is  an  apparent  resem- 
blance between  light  and  gravitation  in  the  fact  that 
both  vary  inversely  as  the  squares  of   the  distances. 
But  this  resemblance  is  more  apparent   than   real, — 
though,   when  we  look   deeper  into  the  problem,    we 
shall   find  that,  after  all,  the   resemblance  at  bottom 
is  based  upon  the  same  principle  of  divergent  radia- 
tion.     Thus :     Light  diminishes  as  the  square  of  the 
distance  increases  only  per  unit  of  area,  and  not  at  all 


140  GRAVITATION. 

in  quantity.     It  is  spread  out  thinner,  so  to  speak  - 
that  is,  over  a  wider  area ;  but  if  a  convex  lens  could  be 
interposed  of  sufficient  dimensions  to  receive  all  the 
diverging  rays  from  any  point,  they  could  all  be  re-col- 
lected without  loss. 

Not  so  with  gravitation.  There  is,  relatively  to  any 
given  mass,  an  .absolute  absence  of  the  force  at  any 
point  proportioned  to  the  square  of  the  distance.  In 
the  case  of  light,  if  a  screen  of  one  square  foot  were 
placed  one  foot  from  a  candle  and  another  of  four 
square  feet  at  the  distance  of  two  feet,  the  quantity  of 
light  falling  on  each  would  be  the  same.  But  one 
cubic  foot  of  iron  at  the  distance  of  8,000  miles  from 
the  centre  of  the  earth  will  weigh  only  one-fourth  as 
much  as  a  similar  block  at  the  distance  of  4,000  miles, 
and  there  is  no  way  in  which  we  can  conceive  the  first- 
mentioned  block  to  be  expanded  so  as  to  receive  the 
same  amount  of  gravitative  force  as  the  second.  Re- 
latively to  the  mass,  the  force  is  not  present,  whether 
the  mass  occupy  much  space  or  little. 

3.  In  apparent  contravention,  though  really  con- 
sistent with  the  foregoing,  is  this  contrast  between 
light  and  gravitation.  While  light  at  any  distance 
from  the  luminous  body  can  neither  be  increased  nor 
diminished  in  quantity,  but  only  dispersed  by  diver- 
gence, and  is  strictly  limited  in  amount,  gravitation  on 
the  contrary  is  practically  infinite.  It  can  handle 
Jupiter  as  easily  as  the  earth,  though  the  former  has 
three  hundred  and  thirty-eight  times  the  mass  of  the 
latter ;  yea,  as  easily  as  it  can  handle  the  asteroids, 
which  are  literally  the  star  dust  of  our  system.  If 
the  earth  were  doubled  in  mass  or  multiplied  by  a 


GRAVITATION  COMPARED  WITH  LIGHT  AND  HEAT.     141 

hundred,  with  or  without  increase  of  volume,  gravita- 
tion would  move  it  with  the  same  ease  as  at  present. 

4.  Again ;    the   heat   rays   are   distinguished   from 
those  of  gravitation  in  this  : 

We  receive  the  rays  of  heat  only  from  sources  com- 
paratively near,  mainly  from  the  sun  and  in  very 
slight  degree  by  reflection  from  the  planets  and  satel- 
lites. The  fixed  stars,  if  we  believe  them  to  be  infinite 
in  number,  even  though  they  are  located  at  almost 
infinite  distances,  ought,  in  virtue  of  their  infinite 
number,  to  send  down  upon  us  floods  of  light  with 
a  corresponding  degree  of  heat,  if  their  emanations  at 
our  distance  were  of  the  same  kind  as  those  of  the  sun. 
The  fact  that  they  do  not  shows  that  the  emanations 
from  the  stars,  though  they  were  as  highly  luminiferous 
and  thermaniferous  as  those  of  our  sun  on  first  leaving 
their  sources,  are  as  cold  as  the  waves  of  gravitation  on 
reaching  our  earth. 

5.  Another  most  significant  point  of  difference  is 
that  in  the  case  of  light  we  reckon  the  divergence  and 
dispersion  from  any  point  on  the  surface  of  the  sun  or 
luminous  body,  but  in  the  case  of  gravitation  we  can 
only  reckon  from  the  centre  of  the  sun  or  other  mass. 

All  these  resemblances  are  beautifully  accounted  for, 
and  all  these  points  of  difference  explained  and  har- 
monized by  the  theory  here  advanced.  With  deference 
I  may  venture  the  question  :  Is  there  any  other  theory 
existent  or  possible  that  can  explain  and  reconcile  all 
these  facts  ? 

The  writer  believes  he  would  be  fully  justified  in 
resting  here  without  one  word  of  comment  upon  the 
foregoing  comparison,  trusting  entirely  to  the  astute- 
ness of  his  readers  to  make  the  application. 


142  GRAVITATION. 

For  example ;  if  the  first  resemblance  be  conceded, 
to-wit :  that  light  and  gravitation  are  both  forms  of 
energy  propagated  through  the  ether  by  vibrations, 
then  the  waves  of  gravitation,  like  those  of  light,  must 
be  forward  from  the  sender  toward  the  receiver.  But 
the  waves  of  light  are  outward  from  the  sun,  while  the 
waves  of  gravitation  are  inward  toward  the  sun  or 
other  centre  of  gravitation.  It  follows  inevitably  that 
the  senders  of  the  waves  of  gravitation  are  the  distant 
suns  of  space. 

Again  I  remark  in  explanation  of  contrast  No.  2 : 

The  wraves  of  gravitation  in  their  inception  do  not 
simply  resemble  those  of  light  and  heat,  but  are  identi- 
cal with  the  latter.  But  in  the  process  of  propagation 
through  infinite  space  they  suffer,  not  diminution,  but 
degradation  and  specialization  that  fit  them  for  their 
appointed  work.  From  the  fact  that  these  waves  are 
supposed  to  emanate  from  every  star,  they  must  be 
propagated  in  all  possible  directions,  and  the  particular 
waves  which,  by  impact  and  interception,  impel  the 
earth  toward  the  sun,  and  the  sun  toward  the  earth  will 
be  converging  instead  of  diverging  rays ;  and  the  par- 
tial interception  of  these  waves  by  any  particle  or  mass, 
as  the  sun,  diminishing  outwardly,  shows  how  this 
force  must  diminish  actually,  and  not  simply  appar- 
ently, with  the  increase  of  the  square  of  the  distance. 

Again ;  if  gravitation  were  an  emanation  from  the 
sun,  like  light,  it  would  like  light  be  finite  in  amount 
and  could  not  be  increased  to  infinity  by  increasing  the 
amount  of  work  to  be  done.  But  the  propulsions  from 
an  infinite  number  of  suns  form  an  infinite  force, 
wherever  there  is  a  corresponding  amount  of  work  to  be 
done.  No  mass  is  great  enough  to  resist  its  power. 


GRAVITATION  COMPARED  WITH  LIGHT  AND  HEAT.     143 

While  it  cannot  rustle  a  leaf,  it  can  easily  lift  a  world. 
Finally,  these  resemblances  and  contrasts  find  their 
culmination  in  the  absolute  identity  of  the  forces  of 
gravitation  and  solar  light  and  heat,  not  by  contraction 
of  the  sun,  but  by  simple  transformation  of  energy. 
The  sun  was  made  grandly  massive  in  order  to  intercept 
correspondingly  large  amounts  of  the  cold  waves  of 
ether.  The  planets  in  comparison  with  the  whole 
heavens  are  only  specks,  and  intercept  a  correspond- 
ingly small  amount  of  these  waves.  The  sun  himself 
receives,  within  an  almost  infinitesimal  quantity,  the 
same  amount  which  he  would  receive  were  the  planets 
of  our  system  non-existent. 

These  waves  change  front  at  the  sun's  surface  and 
start  anew  on  their  extended  progresses  through 
space.  They  change  suddenly  to  heat  at  the  sun,  but 
slowly  and  gradually  back  to  waves  of  force  during 
their  progress  through  the  illimitable  fields  of  ether. 

So  of  all  the  other  points,  both  of  resemblance  and 
contrast ;  there  is  not  one  of  them  from  which  the  same 
lesson  cannot  be  read  in  whole  or  in  part.  If  it  requires 
a  little  thought  on  the  part  of  our  readers,  we  are  not 
unwilling  to  share  with  them  the  ennobling  pleasure. 

Gravitation,  by  means  of  little  impulses  or  blows  by 
ethereal  atoms,  keeps  St.  Peter's  in  Home,  St.  Paul's  in 
London,  and  Trinity  in  New  York,  pressed  down  upon 
their  foundations.  It  keeps  the  rivers  in  their  channels 
and  pushes  them  forward  toward  the  ocean.  It  keeps 
the  oceans  in  their  beds  and  by  its  myriad  pulsations 
causes  them  to  rise  and  sink  in  the  tides.  It  keeps  the 
mountains  seated  on  their  thrones,  the  planets  circling 
in  their  orbits,  the  sun  in  his  appointed  place,  and  binds 
all  the  stars  in  their  courses. 


CHAPTER  VIII. 

ILLUSTRATIONS     OF     GRAVITATION    AND     WEIGHT- 
SEMI-DELUSIONS. 

Away !  away !  through  the  wide,  wide  sky, 

The  fair  blue  fields  that  before  us  lie ; 

Each  sun  with  the  worlds  that  around  us  roll, 

Each  planet  poised  on  her  turning  pole, 

With  her  isles  of  green,  and  her  clouds  of  white, 

And  her  waters  that  lie  like  fluid  light.          —  BRYANT. 

BEHOLD  a  dozen  men  lifting  with  all  their  strength 
upon  a  heavy  timber.  They  are  struggling  and 
staggering  under  a  very  powerful  but  invisible  opposing 
force.  What  is  it  ?  I  answer :  An  inconceivable  num- 
ber of  little  round-headed  mallets  without  handles  are 
busy  pounding  on  the  upper  and  interior  surfaces,  in 
fact,  upon  the  upper  side  of  every  particle  of  the  timber, 
with  little  blows,  swinging  through  the  fifty-thousandth 
part  of  an  inch  and  falling  at  the  rate  of  four  hundred 
trillions  per  second  on  every  point,  making  up  in  num- 
ber, as  we  may  well  believe,  what  they  lack  in  indi- 
vidual momentum.* 

This  force  is  a  most  real  one,  as  those  who  are  con- 
tending with  it  well  know.  It  acts  in  a  direction  down- 
ward toward  the  centre  of  the  earth.  There  can  be  no 
mistake  about  this.  It  is  caused. by  actual  matter  press- 
ing downward  upon  the  timber,  for  all  force  is  by  im- 
pact. This  downward  pressing  matter  is  certainly  in- 

*  See  Ntigcnt's  "Optics,"  page  95.    Lockyer's  "  Spectrum  Analysis,"  page  2U. 
144 


GRAVITATION    AND    WEIGHT.  145 

visible,  and  reveals  itself  to  only  one  sense,  that  of 
muscular  action.  "We  cannot  avoid  suspecting  that  this 
downward  pressing  matter  is  ether,  and  when  we  per- 
form a  similar  experiment  in  a  vacuum  where  there  is 
nothing  else,  we  know  it  must  be  ether.  But  if  the 
force  of  gravitation  is  exerted  through  ethereal  vibra- 
tions, the  ether  is  the  medium  only  and  not  the  origina- 
tor of  these  vibrations,  for  ether  originates  no  vibra- 
tions, but  simply  transmits  them  from  their  senders  to 
their  receivers.  What  bodies  are  there  in  the  directions 
from  which  these  undulations  come?  None  but  those 
which  gem  the  firmament  arid  people  immensity. 

The  impulses  producing  these  blows  have  come  all 
the  way  from  the  fixed  stars,  whose  distances  the 
mathematicians  cannot  measure,  using  for  units  millions 
of  miles.  The  timber  is  pushed  in  one  direction  only, 
because  the  earth  cuts  off  an  almost  equal  number  of 
blows  that  would  otherwise  strike  upon  it  from  an  op- 
posite direction. 

How  little  do  these  honest  toilers  imagine  the  nature 
or  source  of  the  power  with  which  they  are  contending ! 
And  yet  I  hold  this  to  be  no  chimera,  but  sober,  literal 
fact.  The  farther  an  object  is  from  the  earth  the  less 
is  the  force  with  which  it  is  impelled  toward  the  earth, 
because  the  greater  wTill  be  the  number  of  these  im- 
pulses or  vibrations  that  will  reach  it  from  all  other 
points  in  the  heavens  and  the  smaller  will  be  the  num- 
ber intercepted  by  the  earth. 

"  Ingenious,"  I  hear  some  one  suggest,  "  but  is  it 
true?"  Let  us  see.  The  existence  of  the  ether  and 
its  vibratory  function  need  not  be  here  re-proved.  Of 
how  many  kinds  these  vibrations  consist  I  will  not  at- 
tempt to  show,  but  one  of  the  principal  is  certainly  the 
10 


146  GRAVITATION. 

normal  or  forward-and-back  motion  in  all  the  lines  of 
propagation. 

But  returning  to  the  ether  as  the  medium  of  these 
vibrations :  Every  oscillation  strikes  upon  the  timber, 
not  on  the  surface  only,  but  upon  every  interior  par- 
ticle. Now  if  these  blows  or  impulses  are  not  delivered 
through  the  ether  as  a  medium,  through  what  medium 
are  they  delivered  ?  Those  impulses  which  impel  the 
earth  toward  the  sun  certainly  come  from  sources  ex- 
ternal to  the  earth's  orbit  and  on  an  average  at  right 
angles  to  it.  They  certainly  originate  proximately  from 
non-ethereal  matter,  for  ether  only  propagates  and 
never  originates  ethereal  vibrations.  But  what  bodies 
are  there  outside  of  the  earth's  orbit  so  situated  as  to  be 
able  to  send  out  undulations  crossing  this  orbit  in  all 
directions?  The  answer  is  self-evident,  to- wit:  the 
fixed  stars  and  celestial  bodies  generally.  It  is  true 
that  there  are  a  few  planets  external  to  the  earth's 
orbit,  but  their  influence  except  as  interceptors  would 
be  infinitesimal.  The  suns  by  their  intense  heat  are 
almost  the  only  disturbers  of  the  ether,  and  by  this 
disturbance  give  rise  to  undulations  of  heat  in  the  first 
instance,  which  ultimately  become  specialized  into  all 
the  other  forms  of  energy. 

I  appeal  to  the  candid  reader,  is  there  any  other 
explanation  possible  ? 

SEMI-DELUSIONS. 

The  ether  is  so  very  ethereal  that  though  its  reality  is 
formally  admitted  by  all,  still  to  many  it  seems  more 
like  an  ideal  than  a  real  existence.  Such  should  re- 
peat Faraday's  experiment  and  attempt  to  cut  through 
the  ether  between  the  poles  of  a  powerful  electro  mag- 
net with  a  silver  case-knife.  They  would  find  that  it 


SEMI-DELUSIONS.  147 

requires  almost  as  much  effort  as  it  would  to  cut 
through  a  soft  cheese.  All  this  resistance  is  due  to  the 
condensation,  or  more  probably  to  a  peculiar  vibration, 
of  the  ether  which  causes  it  to  resist  the  interpenetra- 
tioii  of  other  bodies.  Whatever  be  the  state  of  the 
ether,  the  resistance  is  due  to  its  presence  alone,  as  the 
resistance  of  still  air  to  the  edge  of  a  knife  is  inappre- 
ciable.* 

The  particles  of  ether,  like  all  other  ultimate  par- 
ticles, are  without  heads,  arms,  hands  or  feet,  and  round 
as  a  bullet.  One  can  set  another  in  motion  only  by 
humping  against  it  bodily.  They  have  no  tentacles  by 
means  of  which  they  can  reach  forth  and  grasp  other 
particles  near  or  remote  and  draw  the  latter  toward  them- 
selves. Newton  perceived  intuitively,  and  we  may  do 
the  same,  that  all  physical  force  is  vis  impressa  and  vis 
a  teryo  ;  that  is,  it  is  exerted  only  by  impact  and  pro- 
pulsion. 

Another  semi-delusion  is  this :  Every  one  admits  in 
a  general  way  that  all  matter,  ethereal  matter  included, 
is  inert.  This  is  taught  in  the  text-books  and  even 
in  our  common  schools;  and  yet  it  is  only  half  be- 
lieved. Many  believe  that  the  sun  is  self-luminous ; 
that  a  peculiar  attraction  resides  in  the  magnet;  that 
chemical  affinity  is  deeply  seated  in  the  elementary 
particles ;  and  especially  that  attraction  of  gravitation 
is  inherent  in  every  particle  in  the  universe.  Now 
if  matter  is  inert,  it  is  absolutely  so.  There  are  no 
such  words  in  our  language  as  inerter  and  inertest. 
It  admits  of  no  degrees.  The  particles  of  matter  are 
admirably  adapted  to  receive  and  transmit  motion  of 
various  kinds ;  but  a  particle  can  no  more  act  without 

*  "Heat  as  a  Mode  of  Motion,"  by  Tyndall,  page  49, 


148  GRAVITATION. 

being  first  acted  upon  than  a  corpse  can  arise  and  walk 
by  its  own  unaided  power.  Particles  move  and  set 
other  particles  in  motion  only  in  virtue  of  a  prior 
impact  from  still  other  moving  particles,  and  thus  back- 
ward to  the  primal  impulse,  or  until  lost  to  us  in  the 
depths  of  a  preterient  eternity.  The  particles  com- 
posing the  sun,  the  earth,  the  ether,  the  universe,  are  all 
alike  in  these  respects.  They  all  act  by  impact  of 
other  particles ;  they  all  act  propulsively ;  they  all  act 
first  upon  their  nearest  neighbors  and  upon  distant 
objects  only  through  intervening  particles;  none  of 
them  act  by  an  inherent  force  —  suo  vigore  /  they  all 
act  by  virtue  of  motion  communicated  to  them  by  other 
particles  in  a  backward  series  ad  injinitum.  It  is  true 
that  the  best  writers  on  physics  often  speak  of  par- 
ticular motions  or  vibrations  as  originating  with  certain 
bodies  as  sources  or  senders,  but  in  all  such  cases  refer- 
ence is  made  to  such  bodies  as  the  proximate  and  not 
the  ultimate  source  of  the  motion. 

It  follows  from  these  premises  that  the  sun  can 
originate  neither  light,  heat,  nor  gravitation.  Light 
and  heat  being  positive  forms  of  energy,  the  sun  re- 
ceives and  sends  them  forth  in  equal  quantities  as 
faithfully  as  a  mirror,  but  with  this  difference :  he 
receives  the  energy  or  motion  under  specialized  forms, 
and  issues  it,  without  exacting  toll,  in  the  general  or 
unspecialized  form  of  light  and  heat. 

No  more  does  the  sun  originate  the  force  of  gravita- 
tion. He  directs  it  toward  himself  by  intercepting  the 
waves  of  mechanical  force  with  which  the  ether  is 
charged,  thus  surrounding  himself  with  what  we  may 
call,  for  want  of  a  better  term,  a  dynamical  shadow, 
diminishing  outwardly  as  the  square  of  the  distance 


WEIGHT.  149 

increases.  This  shadow  extends,  however  faintly,  to 
the  very  confines  of  creation ;  is  everywhere  present, 
and  every  particle  in  the  universe  feels  its  negative 
influence  simultaneously. 

"  Bound  and  round  in  cycles  turn 
The  orbs  that  in  the  empyrean  burn  ; 
Round  and  round  the  forces  flow 
That  feed  the  fires  that  in  them  glow." 

WEIGHT. 

Weight  is  the  tendency  of  bodies  to  fall  toward  the 
eartli  or  some  other  body  by  gravitation.  It  is  not  an 
essential  property  of  matter,  though  usually  so  reck- 
oned.* It  may  be  called  wholly  an  accidental  prop- 
erty, if  anything  in  a  complete  system  may  properly 
be  called  accidental.  It  owes  its  existence  wholly  to 
the  normal  vibrations  of  ether  and  the  fact  that  ordi- 
nary matter  arrests  them,  while  ethereal  matter  does 
not. 

The  normal  vibrations  of  ether  are  forward  and 
back  like  the  motions  of  a  pushing  pawl  on  a  ratchet 
wheel ;  but  the  effect  is  forward  only,  while  the  recoil 
is  only  to  gain  a  standpoint  for  a  renewed  forward 
push.  This  follows  necessarily  from  the  first  original 
push  against  the  ether  by  the  vibrating  matter,  which 
starts  an  ethereal  vibration.  This  push  is  outward  and 
onward  and  so  is  every  repetition  of  it  till  the  first 
impulse  is  delivered  on  the  receiver. 

Ordinary  matter  receives  these  impulses,  but  does 
not  send  them  forward  with  the  lightning  rapidity 

*The  master  (Newton)  had  taken  an  excess  of  precautions,  as  I  have  just 
said,  in  order  that  there  might  not  be  attributed  to  him  the  idea  of  the  action  of 
bodies  at  a  distance,  and  the  notion  that  weight  is  an  essential  property  of 
matter.—"  Modern  Physics,"  by  Naville,  page  136. 


150  GRAVITATION. 

with  which  they  travel  in  ether.  On  the  contrary, 
in  part  they  push  the  receiving  body  slowly  from  its 
course,  as  in  gravitation  where  a  portion  of  the  neu- 
tralizing waves  are  intercepted  from  the  opposite  side, 
and  also  in  part  they  turn  to  heat  by  arrested  motion. 
Tims  every  body  that  is  so  situated  as  to  be  exposed 
to  this  ethereal  bombardment  on  one  side,  and  par- 
tially shielded  from  the  same  on  the  opposite  side, 
will  have  the  property  of  weight.  But  as  each  mole- 
cule in  each  one  of  a  pair  of  balancing  bodies,  such 
as  the  earth  and  sun,  intercepts  one  unit  of  motion 
from  each  molecule  in  the  other,  the  gravitation  of 
each  toward  the  other  will  be  measured  by  the  num- 
ber of  molecules  in  one  body  multiplied  by  the  number 
in  the  other  and  divided  by  the  square  of  the  dis- 
tance between  their  centres.  But  a  body  so  situated  as 
to  be  unshielded  on  all  sides  will  receive  this  ethereal 
bombardment  equally  on  all  sides,  each  impulse  being 
neutralized  by  one  from  an  opposite  direction,  and  the 
body  will  be  without  weight,  no  matter  how  massive. 
It  will  not  fall  in  any  direction. 

A  body  situated  at  the  centre  of  the  earth  or  sun 
wpuld  be  without  weight,  because  the  ethereal  bom- 
bardment would  be  intercepted  to  an  equal  extent  on 
ever}'  side;  so  also  of  a  body  in  the  gravitative  centre 
of  a  system,  as  the  sun.  We  cannot,  however,  extend 
the  principle  to  the  solar  system  as  a  whole  and  say  that 
it  is  without  weight,  being  located  in  the  centre  of  an 
infinite  universe.  The  universe  may  be  infinite  and 
any  point  may  be  assumed  as  a  centre,  and  still  this 
universe  may  be  clustered  into  groups  or  families  of 
suns  and  systems  with  vortical  motions  so  grand  as  to 
paralyze  the  imagination  in  attempting  to  grasp  them. 


WEIGHT.  151 

Tliis  is  the  place,  if  I  have  not  done  so  before,  to 
answer  the  question  why  a  body  near  the  earth  does 
not  weigh  less  in  the  daytime,  when  a  part  of  the 
force  of  gravitation  is  cut  off  by  the  sun,  than  in  the 
night  when  it  is  exposed  to  the  emanations  of  a  whole 
hemisphere  of  the  heavens?  I  answer  that  it  does 
weigh  less  in  the  daytime,  but  only  to  an  extent  that  is 
absolutely  inappreciable  for  any  body  that  can  be 
weighed  by  means  of  ordinary  scales.  This  difference 
could  only  be  detected,  if  at  all,  under  the  most 
favorable  circumstances  by  a  spring  balance,  as  weights 
in  opposite  scales  would  of  course  be  equally  affected. 
I  do  not  despair  of  hearing  that  spring  balances  have 
been  constructed  of  sufficient  delicacy  to  show  that  an 
object  weighs  appreciably  less  at  noonday  under  a  ver- 
tical sun  than  at  midnight. 

But  when  such  bodies  as  oceans  are  weighed  in 
nature's  scales  they  show  these  variations  in  the  tides. 
This,  however,  does  not  necessitate  a  discussion  here 
of  the  theory  and  causes  of  the  tides.  Every  true 
word  that  has  been  written  on  the  subject  of  tides 
applies  on  this  theory  by  substituting  one  word,  "pro- 
pulsion "  for  "attraction,"  and  regarding  the  sun  and 
moon  as  the  negative  instead  of  positive  sources  of 
gravitative  force.  The  oceans  lift  their  broad  faces  to 
meet  the  sun  and  moon,  not  through  attraction,  but 
because  these  luminaries  shield  them  in  part  from 
the  stellar  waves  that  would  otherwise  force  them  back 
to  the  common  level. 


CHAPTER  IX. 

LE  SAGE'S  ULTRAMUNDANE  CORPUSCLES. 

Wide  through  the  waste  of  ether,  sun,  or  star, 
All  linked  by  Harmony,  which  is  the  chain 

Which  binds  to  earth  the  orbs  that  wheel  afar 

Through  the  blue  fields  of  Nature's  wide  domain. 

—  PERCIVAL. 

EVERY  thinker  enjoys  a  kind  of  rapture  over  a 
new-born  thought  or  discovery,  akin  to  that  of 
Count  Rumford  on  his  discovery  of  the  identity  of  heat 
and  motion.  But  how  often  is  that  rapture  dashed,  on 
discovering  the  same  thought  or  discovery  anticipated 
by  another. 

I  know  not  how  often  I  may  have  been  anticipated 
in  the  view  of  gravitation  here  presented ;  but  the  only 
theory  I  have  seen  (and  that  after  the  foregoing  pages 
had  been  written),  that  even  remotely  resembles  it,  is 
that  of  Le  Sage,  in  which  he  imagines  that  all  space  is 
filled  with  "  ultramundane  corpuscles,"  flying  in  all  di- 
rections with  inconceivable  velocity,  and  impinging  on 
all  sides  of  the  celestial  bodies,  except  where  these  bodies 
operate  as  screens  to  each  other.  It  is  only  in  this  last 
respect  that  any  resemblance  exists  between  his  theory 
and  the  one  here  presented. 

The  theory  of  Le  Sage  was  unsatisfactory  to  himself 
and  is  almost,  if  not  wholly,  without  adherents.  These 
ultramundane  corpuscles,  if  they  exist,  must  be  elastic 
or  inelastic.  If  elastic,,  they  must  be  in  a  state  of  con- 

152 


LE  SAGE'S  ULTRAMUNDANE  CORPUSCLES.         153 

stant  resilience  from  mutual  impact,  and  would  exert 
no  force  upon  the  earth,  or  any  other  body.  All  their 
energy  would  be  employed  upon  each  other,  and  their 
direction  would  be  changing  every  moment,  whereas 
the  waves  of  ether  move  always  in  right  lines.  If  in- 
elastic, the  motions  of  all  the  particles  would  neutralize 
each  other.  The  corpuscles  would  come  to  a  dead 
standstill,  and  their  translator^  motion  would  be  changed 
to  heat.  In  neither  case  would  it  be  possible  for  these 
particles  to  change  the  directions  of  the  earth  and  other 
bodies  moving  through  space.  Undulations  can  and  do 
move  in  opposite  and  in  all  directions  through  the  same 
medium  without  destroying  each  other ;  but  material 
bodies  cannot  move  by  actual  transference  on  the  same 
line  in  opposite  directions  without  destroying  each  other's 
motion. 

Besides,  it  is  small  satisfaction  to  be  told  about  "  ul- 
tramundane corpuscles  from  unknown  regions"  Better 
dismiss  the  subject,  as  many  have  done,  as  the  unex- 
plained effect  of  an  unknown  cause.  Particles  of  mat- 
ter do  not  spontaneously  leave  the  earth  in  defiance  of 
the  law  of  gravitation,  and  fly  to  other  worlds.  Neither 
do  we  recognize  the  arrival  on  earth  of  such  particles 
from  other  regions,  known  or  unknown. 

The  ashes  of  meteors  have  no  resemblance  to  Le 
Sage's  corpuscles.  Long  ago  the  Newtonian  theory  of 
luminiferous  corpuscles  had  to  be  abandoned  in  favor 
of  undulations ;  and  there  is  not  an  argument  against 
light  corpuscles  that  is  not  equally  valid  against  gravi- 
tation corpuscles ;  and  I  will  add,  there  is  not  an  argu- 
ment in  favor  of  luminiferous  undulations  that  cannot 
be  paralleled  by  an  equally  strong  one  in  favor  of  grav- 
itation undulations. 


154  GRAVITATION. 

It  is  unnecessary  to  expose  here  the  impossibility  of 
material  corpuscles  penetrating  all  bodies,  solid,  liquid, 
and  gaseous,  through  and  through,  so  as  to  reach  and 
operate  upon  every  interior  molecule.  Yet  this  is  what 
gravitation  does,  and  I  here  submit  the  question  to 
every  candid  mind  :  Is  it  possible  for  any  force,  except 
one  acting  by  undulations  of  an  all-pervading  ether,  to 
reach  and  act  upon  every  interior  molecule  composing 
the  earth  and  the  sun  ? 

If  one  of  Le  Sage's  ultramundane  corpuscles,  or,  as 
we  would  now  call  them,  molecules,  should  penetrate 
bodily  into  the  inner  recesses  of  the  planet,  seek  out  a 
mundane  molecule,  impinge  against  it,  and  thus  be 
stopped  by  the  collision,  it  would  of  course  rest  where 
the  collision  occurred,  and  the  very  first  impulse  of 
gravitation  would,  on  Le  Sage's  theory,  result  in  doub- 
ling the  mass  of  the  earth.  Two  particles  can  no  more 
meet  squarely  on  the  same  line  and  pass  each  other  than 
can  two  cannon  balls  or  two  planets. 

Undulations  of  an  all-pervading  medium  can  reach 
and  act  upon  every  molecule  in  the  earth,  communicat- 
ing motion,  and  leaving  nothing  but  motion  behind,  but 
if  this  motion  were  communicated  by  the  arrival  of 
actual  corpuscles,  they  would,  when  stopped,  leave 
themselves  behind. 

NOTE.— It  might  be  said  that  even  ethereal  vibrations  acting  in  all  possible 
directions  at  the  same  time  would  exactly  neutralize  each  other,  and  produce  a 
perfectly  motionless  condition  of  the  ether.  This  would  certainly  be  so,  if  these 
vibrations  were  absolutely  simultaneous.  It  would  be  a  point-blank  contradic- 
tion to  say  that  a  particle  of  ether  could  move  in  two  opposite  directions  at  the 
same  instant  of  time.  But  if,  as  is  well  known,  the  particles  make  from  four 
to  seven  hundred  trillion  vibrations  in  a  second,  it  is  easy  to  see  that  far-reach- 
ing lines  of  active  force  may  actually  be  propagated  in  all  directions  without 
mutual  interference,  but  capable  of  delivering  their  motion  to  ordinary  matter 
when  arrested  by  the  same. 


CHAPTEK   X. 

OMNIPOTENT  ATOMS— ASTRONOMICAL  AND  OTHER  OB- 
JECTIONS TO  TOE  AVAILABILITY  OF  ETHER 
IN  PRODUCING  GRAVITATION. 

The  particle  A  will  attract  the  particle  B  at  the  distance  of  a 
mile  with  a  certain  degree  of  force;  it  will  attract  a  particle  C  at  the 
same  distance  of  a  mile  witli  a  power  equal  to  that  by  which  it 
attracts  B;  if  myriads  of  like  particles  be  placed  at  the  given  dis- 
tance of  a  mile,  A  will  attract  each  with  equal  force;  and  if  other 
particles  be  accumulated  round  it,  within  and  without  the  sphere  of 
two  miles  diameter,  it  will  attract  them  all  with  a  force  varying  in- 
versely with  the  square  of  the  distance.  How  are  we  to  conceive  of 
this  force  growing  up  in  A  to  a  millionfold  or  more,  and  if  the  sur- 
rounding particles  be  then  removed,  of  its  diminution  in  an  equal 
degree?  Or,  how  are  we  to  look  upon  the  power  raised  up  in  all 
these  other  particles  by  the  action  of  A  on  them,  or  by  their  action 
on  one  another,  without  admitting,  according  to  the  limited  defini- 
tion of  gravitation,  the  facile  generation  and  annihilation  of  force? 

For  my  own  part,  many  considerations  urge  my  mind  toward 
the  idea  of  a  cause  of  gravity,  which  is  not  resident  in  the  particles 
of  matter  merely,  but  constantly  in  them  and  all  space.  I  have 
already  put  forth  considerations  regarding  gravity  which  partake  of 
this  idea,  and  it  seems  to  have  been  unhesitatingly  accepted  by 
Newton.* — DR.  FARADAY. 

I  HA  YE   introduced   this  chapter  by  an  unusually 
long  quotation,  and  from  one  of  the  clearest  think- 
ers and  closest  reasoners  of  this  century,  in  order  to 
show  the  impossibility  of  gravitation  by  an  inherent 
power  residing  in  the  particles,  unless  these  particles 

*  "Correlation  and  Conservation  of  Forces."    Compiled  by  E.  L.  Youmans, 
155 


156  GRAVITATION. 

are  endowed  with  creative  power.  If  they  are,  it  is 
time  that  a  new  cultus  were  established  for  the  worship 
of  the  Almighty  Atom. 

I  have  endeavored  elsewhere  to  present  the  plan  by 
which  every  particle,  instead  of  exerting  creative 
power,  is  privileged  to  draw  upon  every  other  particle 
in  the  universe,  not  as  the  originators,  but  as  the  media 
of  transmission,  of  vibratory  forces  as  old  as  creation 
itself. 

As  the  sources  of  gravitation  are  infinite,  it  is  equal 
to  any  conceivable  amount  of  work  that  can  be  pre- 
sented to  it.  This  explanation  exactly  solves  the  mys- 
tery so  forcibly  stated  by  Dr.  Faraday.  Particle  A, 
unless  omnipotent,  could  not  exert  an  infinite  force ;  but 
as  one  of  the  centres  of  an  infinite  universe  it  can 
receive,  and  by  its  inertia  arrest,  an  infinite  number  of 
impulses  from  every  possible  direction,  and  thus  inter- 
cept these  impulses  from  other  particles. 

Each  of  these  other  particles  intercepts  the  same 
number  of  impulses  from  the  first,  and  so  lines  of  least 
resistance  are  established,  on  which  all  particles  will 
tend  to  approach  each  other  in  inverse  proportion  to 
the  squares  of  the  distances. 

The  present  orthodox  doctrine  in  regard  to  gravita- 
tion is,  that  it  is  an  unexplainable  mystery,  and  any 
attempt  at  explanation,  no  matter  by  what  means,  must 
for  a  long  time  be  regarded  with  the  disfavor,  if  not 
the  odium,  of  heresy  in  science.  In  view  of  the 
strongly  entrenched  position  of  this  prejudice,  I  shall 
not  hesitate  to  repeat  any  valid  argument  that  will  tend 
to  dislodge  it. 

It  has  been  considered  an  insuperable  objection  to 
any  use  of  ethereal  undulations  in  producing  gravita- 


OMNIPOTENT    ATOMS.  157 

tion,  that  all  such  undulations  must  require  appreciable 
time  in  travelling  from  the  sun  to  the  earth,  while 
gravitation  is  instantaneous.  Thus  Arago : 

"  If  attraction  is  the  result  of  the  impulsion  of  a  fluid  [ether,  for 
example],  its  action  must  employ  a  finite  time  in  traversing  the  im- 
mense spaces  which  separate  the  celestial  bodies;  whereas  there  is 
no  longer  any  reason  to  doubt  that  the  action  of  gravity  is  instan- 
taneous."—  Stallo's  "Modern  Physics,"  page  60. 

The  error  here  is  in  assuming  that  the  undulations 
of  gravitation  originate  at  the  sun  and  proceed  out- 
wardly to  the  orbits  of  the  planets,  whereas  just  the 
opposite  is  the  fact.  Undulations  are  passing  and  re- 
passing  in  all  directions  from  all  bodies  to  all  others, 
but  the  particular  undulations  that  impel  the  "earth 
toward  the  sun  come  from  directions  opposite  from  the 
sun,  ££  ovpavtbv,  and  as  they  are  always  present  to  the 
earth  at  every  point  in  its  orbit,  they  take  effect  instan- 
taneously the  moment  the  earth  arrives  at  any  and 
every  point. 

How  else,  I  will  most  respectfully  ask  the  intelligent 
reader,  is  it  possible  for  the  force  of  gravitation  to  act 
instantaneously,  unless  it  is  a  force  present  and  ready  to 
act  at  every  point  in  the  earth's  orbit  at  and  even  before 
the  earth's  arrival?  And  how  can  there  be  action  in 
pure  space,  except  through  the  only  medium  that  per- 
vades all  space  ?  And  how  can  gravitation  act  through 
ether,  except  by  undulations  1  And  where  can  undula- 
tions, passing  athwart  the  earth's  orbit,  and  aimed  at 
the  sun,  originate,  except  in  the  starry  concave  ?  The 
instantaneous  action  of  gravitation,  instead  of  disprov- 
ing, conclusively  proves  the  cosmic  origin  of  this  force, 
and  its  transmission  by  ethereal  undulations  aimed  at 
the  sun  and  earth  respectively. 


158  GRAVITATION. 

OTHER  OBJECTIONS. 

As  I  desire  to  answer  every  possible  objection  with 
the  utmost  candor,  I  will  quote  from  the  work  last 
named  a  summary  of  the  main  objection  to  ethereal 
undulations,  thus : 

"There  are,  moreover,  as  Mr.  Taylor  has  observed,  other  features 
of  gravitation  which  give  rise  to  the  presumption  that  it  is  of  a 
nature  essentially  different  from  that  of  other  forms  of  radial  action. 
(1)  The  action  of  gravity  is  wholly  unsusceptible  of  interference  by 
intervening  obstacles,  or,  as  Jevons  expresses  it,  'All  bodies  are,  as 
it  were,  absolutely  transparent  to  it.'  (2)  Its  direction  is  in  right 
lines  between  the  centres  of  the  attracting  masses.  (3)  It  is  not 
subject  to  reflection  or  refraction.  (4)  Unlike  the  forces  of  cohesion, 
capillarity,  chemical  affinity,  and  electric  or  magnetic  attraction,  it 
is  incapable  of  exhaustion,  or,  rather,  saturation,  every  body  attract- 
ing every  other  in  proportion  to  its  mass.  (5)  It  is  wholly  inde- 
pendent of  the  nature,  volume,  or  structure  of  the  bodies  between 
which  it  occurs,  and  (6)  Its  energy  is  unchangeable,  incessant,  and 
inexhaustible." — Stallo's  "Modern  Physics,"  page  62. 

Iii  all  these  respects  gravitation  is  sought,  not  only 
to  be  distinguished,  but  divorced  from  all  other  forms 
of  energy.  Yet  in  detiance  of  these  decrees,  it  mingles 
freely  in  all  mundane  affairs,  and  assumes  in  turn  every 
known  form  of  energy.  These  are  the  strongest  objec- 
tions that  can  be  urged  to  the  radial  nature  of  gravita- 
tion. 

Let  us  examine  them  in  order. 

First  proposition :  "  That  gravity  is  wholly  unsus- 
ceptible of  interference  by  intervening  obstacles,  and 
that  all  bodies  are  absolutely  transparent  to  it." 

Answer:  This  we  verily  believe  to  be  a  mistake. 
Gravitation  penetrates  the  earth  and  every  celestial 
body  through  and  through,  because  they  are  permeated 
through  and  through  by  ether.  But  it  emerges  very 
much  weaker  than  it  entered.  Nothing  has  been  lost, 


OTHER    OBJECTIONS.  159 

but  every  molecule  of  matter  encountered  in  its  passage 
through  the  earth  has  absorbed  one  unit  of  motion. 
Hence  all  around  the  earth,  and  travelling  with  it,  is  a 
region  in  which  the  incoming  waves  are  in  full  force 
and  vigor,  but  the  outgoing  ones  are  feeble,  if  not 
extinct,  from  terrestrial  absorption  or  interception. 
Hence  any  body  within  the  sphere  of  the  action  of 
these  two  unequal  forces  will  be  impelled  in  the  direc- 
tion of  the  least  resistance,  -/.<?.,  toward  the  earth ;  and 
this  is  gravitation. 

Let  any  one  enter  a  deep  mine,  or  go  through  a  tun- 
nel under  a  high  mountain  ;  he  \vill  find  all  objects, 
even  his  own  body,  weighing  less  on  a  delicate  spring 
balance  than  if  weighed  above  ground ;  and  this  decrease 
extends  to  the  centre  of  the  earth.  This  shows  that 
the  action  of  gravity  in  passing  through  the  earth  loses 
a  portion  of  its  force.  Experiments  have  shown  that 
objects  weighed  under  a  heavy  block  of  lead  suspended 
in  the  air  will  weigh  less  than  if  weighed  at  one  side. 
This  will  be  called  counter-attraction,  but  the  fact 
remains,  by  whatever  name  it  is  called.  Besides,  we 
are  justified,  on  the  authority  of  Newton,  in  pronounc- 
ing a  force  acting  by  attraction  to  be  an  impossibility, 
and  that  propulsion  by  impact  is  the  only  mode  by 
which  nature's  forces  act. 

Second  proposition :  "  Its  direction  is  in  right  lines 
between  the  centres  of  the  attracting  masses." 

Answer:  Its  direction,  truly,  is  in  right  lines,  but 
so  far  from  proving  that  this  action  is  not  radial  action 
through  ether,  it  proves  just  the  contrary.  All  radial 
action  is  in  right  lines,  while  no  other  kind  of  physical 
action  is  so.  It  is  not  directed  exclusively  to  the  centres 


160  GRAVITATION. 

of  the  masses,  but  to  all  parts,  averaging  as  if  directed 
to  the  centres. 

Third  proposition:  "It  is  not  subject  to  reflection 
nor  refraction." 

Answer :  This  is  not  conceded  so  far  as  reflection  is 
concerned,  though  it  might  be,  and  yet  have  no  ten- 
dency to  prove  that  gravitation  is  not  radial  action 
through  ethereal  vibrations. 

Fourth  proposition  :  "  Unlike  the  forces  of  cohesion, 
capillarity,  chemical  affinity,  and  electric  or  magnetic 
attraction,  it  is  incapable  of  exhaustion,  or,  rather,  satu- 
ration, every  body  attracting  every  other  in  proportion 
to  its  mass." 

Answer :  It  is  incapable  of  exhaustion,  because  all 
matter  is  in  a  state  of  insensible  tremor,  receiving  and 
giving  out  vibrations  ceaselessly,  and  the  ether  is  the 
common  carrier  of  them  all,  carrying  away  and  bring- 
ing back  to  every  molecule  on  an  average  the  same 
amount  of  motion  in  a  never  ending  circuit.  Exhaustion 
is  therefore  an  impossibility. 

This  molecular  vibration  is  an  ultimate  fact,  not 
because  it  is  a  necessary  property  of  molecules  to 
vibrate  ;  they  are  just  as  capable  of  complete  rest,  when 
set  at  rest  by  transference  of  their  motion,  as  of  slow 
or  rapid  vibration.  Every  body,  great  and  small,  is 
like  the  pendulum.  It  will  move  if  set  in  motion,  and 
rest  if  set  at  rest.  A  given  amount  of  motion  has  been 
Injected  into  nature,  which  may  change  in  form,  or 
change  its  subject,  but  remains  forever  in  action  without 
increase  or  diminution. 

Fifth  proposition :  "  It  is  wholly  independent  of 
the  nature,  volume  or  structure  of  the  bodies  between 
which  it  occurs." 


OTHER   OBJECTIONS.  161 

Answer :  It  is  difficult  to  see  how  this  fact  tends  to 
prove  that  the  action  of  gravitation  is  not  radial  by 
means  of  the  ether.  It  is  independent  of  the  nature, 
volume,  etc.,  because  gravitation,  as  all  admit,  is  the 
action  of  molecules  upon  molecules.  But,  as  the  mole- 
cules between  which  gravitation  acts  are  separated  by 
millions,  and  hundreds  and  thousands  of  millions,  of 
miles,  this  intermolecular  action  can  only  take  place 
through  an  intervening  medium.  Do  we  know  of  any 
except  the  ether? 

Sixth  proposition  :  "  Its  energy  is  unchangeable,  in- 
cessant and  inexhaustible." 

Answer :  Does  this  prove  that  gravitation  is  not 
radial  action  through  ether?  On  the  contrary,  it  is 
unchangeable,  incessant  and  inexhaustible  because  its 
source  is  unchangeable,  incessant  and  inexhaustible. 
But  this  could  not  possibly  be  so,  unless  it  moves  in  a 
never-ending  circuit. 

Like  all  other  forms  of  radial  action  it  proceeds  in 
right  lines.  Like  all  other  forms  it  is  capable  of  par- 
tial diminution  in  passing  through  media  other  than 
ether,  leaving  a  part  of  its  motion  in  the  resisting  me- 
dium. Like  all  other  forms  it  proceeds  from  non- 
ethereal  senders  to  non-ethereal  receivers  through  the 
ethereal  medium.  Like  all  other  forms  it  observes  the 
greatest  prodigality  in  the  distribution  of  its  favors  and 
at  the  same  time  a  penuriousness  that  allows  nothing  to 
be  lost. 

Like  energy  under  other  names  it  changes  its  form, 
but  conserves  its  existence  without  increase  or  diminu- 
tion. Instead  of  being  "essentially  different,"  I  ask 
how  is  it  possible  for  gravitation  more  closely  to  resem- 
ble all  other  forms  of  "  radial  action  "  ? 
11 


CHAPTEE  XL 
ONTOLOGY. 

Felix  qui  potuit  rerum  cognoscere  causas. —  VIRGIL. 

THIS  discussion  leads  us  perilously  near  the  forbid- 
den border  land  of  Ontology,  which  I  will  prom- 
ise, however,  not  to  invade  further  than  to  ask  a  single 
question,  the  true  answer  to  which,  though  simple  as 
A,  B,  C,  will  wonderfully  clear  our  vision  and  enlarge 
and  correct  our  views  of  nature. 

The  question  is  this :  Taking  universal  nature  at 
any  point  in  her  past  history,  or  better  still,  at  the 
present  moment,  we  find  every  part  in  slow  or  rapid 
motion. 

Why  does  this  motion,  matter  being  naturally  inert, 
seek  to  leave  its  present  subjects  and  transfer  itself  to 
others?  The  simple  answer  is,  because  there  is  not 
in  all  the  wide  domain  of  nature  vacant  space  to 
accommodate  a  single  additional  molecule  of  matter 
without  to  some  extent  crowding  upon  those  now  in 
existence.  Where  there  is  room  for  a  molecule,  a 
molecule  occupies  that  room.  All  space  not  occupied 
by  grosser  matter  is  filled  with  the  invisible  ether. 
Hence  not  a  molecule  can  move  without  jostling  and 
jarring  some  other  molecule  with  which  it  is  in  contact, 
or  quasi  contact.  Not  a  motion  can  take  place  that 
does  not  inaugurate,  or  rather  perpetuate,  a  motion  that 
must  go  on  to  eternity.  The  action  of  gravitation  is 


ONTOLOGY.  163 

a  necessary  sequence  of  this  imperishability  of  motion, 
and  could  long  ago  have  been  demonstrated  a  priori 
like  a  proposition  in  geometry,  if  the  attention  of  a 
mind  of  sufficient  power  had  been  directed  to  the 
subject. 

Suppose  that  at  the  beginning  of  the  sixteenth  cen- 
tury, before  it  was  known  that  the  planets  revolve 
around  the  sun  in  nearly  circular  orbits,  one-half  only 
of  the  truth  had  been  revealed  to  the  great  mind  of 
Copernicus,  viz.,  that  the  earth  was  moving  for  the 
moment  in  the  tangent  of  a  circle  one  hundred  and 
eighty -five  millions  of  miles  in  diameter,  with  the  sun 
at  the  centre,  and  suppose  also  that  he  knew  what 
we  all  now  know,  that  the  universal  ether  is  filled  with 
radiations  of  mechanical  force,  proceeding  outwardly 
in  right  lines  from  every  body  in  space.  From  these 
premises  alone  his  clear  mind  would  have  said,  or  might 
have  said,  "  It  is  impossible  that  the  earth  should  con- 
tinue to  move  in  this  tangent  line.  Some  of  these 
radiations  will  be  intercepted  from  the  earth  by  the 
sun,  and  from  the  sun  by  the  earth,  and  they  will  of 
necessity  tend  to  approach  each  other  on  the  line  of 
least  resistance."  Had  he  also  possessed  the  mathe- 
matical knowledge  of  Newton,  he  could  also  have  said 
that  "the  paths  described  by  the  earth  and  other 
planets  must  be  elliptical  orbits  around  the  sun."  Or 
let  us  take  a  later  date  and  a  greater  mind,  that  of 
Sir  Isaac  Newton.  He  well  knew  the  forms  of  the 
planetary  orbits  and  the  modes  of  action  of  the  forces 
that  control  them.  He  knew  that  the  tangential  was 
an  immanent  force,  not  requiring  renewal  ;  that  the 
centripetal  was  an  active  and  changing,  or  what  we 
now  call  a  working  force.  He  knew  that  all  force  was 


164  GRAVITATION. 

"vis  iinpressa  and  vis  a,  tergo"  that  is,  that  all  force  is 
exerted  by  impact  and  propulsively.  He  knew,  there- 
fore, that  the  earth  could  not  be  drawn  toward  the  sun 
by  attraction  of  that  body,  and  so  declared. 

Although  the  father  of  the  attraction  theory,  he  re- 
jected the  idea  that  attraction  was  a  property  of  matter, 
and  looked  for  this  force  elsewhere.  It  might  seem 
that  Newton  was  slightly  inconsistent  in  defining  all 
force  as  a push  by  impact  and  then  making  gravitation 
a  pull  by  means  of  nothing.  This  is  not  so.  It  is  true 
he  called  it  by  the  name  of  attraction  for  want  of  a 
better,  but  the  only  hypothesis  advanced  by  him  in 
explanation  Avas  a  force  in  the  nature  of  a  push.  He 
conceived  that  portion  of  space,  subject  to  the  sun's 
gravitative  action,  to  be  filled  with  a  fluid  increasing  in 
density  outward  from  the  sun,  instead  of  the  reverse, 
and  that  the  planets  were  thereby  pushed,  not  pulled, 
toward  the  sun,  where  he  conceived  this  fluid  was  less 
dense  and  so  offered  less  resistance.  He  was  not,  how- 
ever, committed  to  this  theory. 

Had  he  also  known  what  is  now  universally  con- 
ceded, viz. :  the  universality  and  undulatory  action  of 
ether  and  the  conservation  of  energy,  he  could  have  de- 
duced the  conclusion,  yea,  he  could  not  have  avoided 
the  conclusion,  that  gravitation  is  produced  by  these  un- 
dulations and  their  interceptions. 

That  he  did  not  arrive  at  this  conclusion  was  proba- 
bly owing  to  the  occupation  of  his  great  mind  with  his 
other  brilliant  discoveries.  Or,  as  he  was  human,  it 
may  have  been  due  to  that  common  infirmity,  which 
causes  us  all  to  say,  as  the  companions  of  Columbus 
said  when  he  made  the  egg  stand  on  end,  u  why  could 
we  not  have  thought  of  that  'i " 


ONTOLOGY.  165 

Ptolemy,  supposing  the  earth  to  be  the  centre  of  our 
system,  conceived  of  a  force,  now  called  gravitation, 
directed  toward,  not  from,  the  centre  of  the  earth,  in 
which  he  was  perfectly  correct,  so  far  as  the  earth  is 
concerned.  Had  lie  known  that  the  sun  was  the  centre 
of  our  system  and  that  the  planets  revolve  around  him, 
as  the  heavenly  bodies  apparently  revolve  around  the 
earth,  he  would,  of  course,  have  taught  that  the  same 
force  on  a  larger  scale  was  directed  toward  the  sun. 

The  sun,  of  course,  sends  out  his  quota  of  the  undu- 
lations of  mechanical  force  which  tend  to  counteract 
the  force  of  gravity,  but  these  are  infinitesimal  in  com- 
parison with  those  issuing  from  the  whole  celestial  con- 
cave. Besides,  I  have  ventured  the  hypothesis  in  which 
I  have  great  confidence,  that  the  very  same  undulations 
which  first  leave  the  sun  of  our  system  and  the  suns  of 
space  in  the  form  of  heat  waves  of  high  amplitude, 
during  their  inconceivably  long  journeys  through  space 
and  time,  though  they  lose  nothing  of  their  aggregate 
energy,  do,  in  virtue  of  their  infinite  diffusion,  change 
their  form  from  heat  waves  to  the  lower  order  of  waves 
of  mechanical  energy.  These  waves  of  mechanical 
force,  if  such  exist,  and  I  believe  this  is  universally  con- 
ceded, must  turn  to  heat,  according  to  the  law  of  ar- 
rested motion,  whenever  they  impinge  upon  any  of  the 
bodies  that  people  the  "  profundities  of  space."  If 
this  be  so,  then  it  is  equally  certain  that  the  waves  of 
heat  must  somewhere  and  under  some  circumstances 
turn  again  to  mechanical  force.  It  is  utterly  impossi- 
ble that  mechanical  force  should  be  constantly  changing 
to  heat,  unless  heat  is  constantly  changing  back  to  me- 
chanical force.  Where  can  this  take  place,  except  on  the 
broad  fields  of  space  ?  How  can  it  take  place  on  these 


166  GRAVITATION. 

broad  fields,  where  there  is  nothing  but  the  universal 
ether  in  vibration,  except  by  these  vibrations  gradually 
changing  their  character  by  diffusion?  Hence  every 
portion  of  this  ether  is  filled  by  two  non-interfering 
kinds  of  waves,  imperceptibly  merging  into  each  other, 
though  their  extremes  are  as  unlike  as  can  be  imagined. 
The  extreme  heat  waves  have  high  amplitude  and  are 
subject  to  refraction.  The  opposite  extreme  is  without 
amplitude,  having  only  the  normal  or  forward -and-back 
motion,  and  therefore  incapable  of  refraction. 

The  force  waves,  moving  in  straight  lines,  impinge  on 
all  sides  of  all  bodies  equally,  except  where  intercepted 
by  these  bodies  from  each  other,  in  which  case  they 
tend  to  push  these  bodies  toward  each  other  according 
to  the  laws  of  gravitation.  But  as  this  function  em- 
ploys but  an  infinitesimal  portion  of  these  waves  of 
force,  the  great  mass  of  them  move  on  forever,  turning 
to  heat  by  arrested  motion  whenever  they  impinge  on 
any  of  the  suns  which  people  immensity. 

Being  again  radiated  into  space  as  heat,  they  pursue 
their  course  in  ever  widening  waves  till  they  are  again 
by  diffusion  turned  to  waves  of  mechanical  motion,  thus 
keeping  up  the  ceaseless  round  of  action  and  change 
without  diminution  or  loss. 


CHAPTER  XII. 

STRESS  —  STRAIN  —  TENSION. 
'Tis  not  in  the  bond. —  SHAKESPEARE. 

STRESS  in  mechanics  is  used  to  denote  the  mutual 
action  between  two  bodies.  Strain  is  tlie  act  of 
exerting  this  stress.  Tension  is  a  stress  exerted  on  a 
rope,  chain  or  string,  tending  to  pull  it  apart.  All 
action  by  two  bodies  upon  each  other  is  either  of  the 
nature  of  a  tension  where  the  action  is  pulling,  or  of  a 
pressure  when  the  bodies  are  impelled  together  by  forces 
exerted  from  without.*  There  can  be  no  tension  with- 
out some  Teal  thing  that  is  tense.  The  qiiality  cannot 
exist  without  the  subject.  If  gravity  is  a  force  exerted 
on  the  earth  by  the  sun  and  on  the  sun  by  the  earth, 
drawing  them  together,  then  there  is  an  actual,  verita- 
ble, literal  and  material  bond,  extending  from  the  sun 
to  the  earth,  analogous  to  a  rope  or  cable,  capable  of 
being  the  subject  of  a  stress  producing  a  tension.  Ten- 
sion is  predicable  only  of  a  material  bond,  capable  of 
being  stretched  or  rendered  tense  by  some  force  pro- 
ducing a  tension.  On  page  79  of  the  work  just  named, 
the  learned  author,  though  not  in  terms  applying  the 
language  to  gravity,  does  describe  with  exactness  the 
kind  and  the  only  kind  of  interaction  between  two  bodies 
at  a  distance,  by  which  they  can  be  brought  together  or 
held  together  by  a  force  exerted  either  between  them  or 
outside  of  them. 

*  See  "  Matter  and  Motion,"  by  J.  Clerk  Maxwell,  page  78,  Van  Nostrand's 
Edition.  167 


168  GRAVITATION. 

His  language  is  as  follows : 

"When  a  tension  is  exerted  between  two  bodies  by  the  medium 
of  a  string,  the  stress,  properly  speaking,  is  between  any  two  parts 
into  which  the  string  may  be  supposed  to  be  divided  by  an  imagin- 
ary section  or  transverse  interface.  *  *  *  Every  portion  of 
the  string  is  in  equilibrium  under  the  action  of  the  tensions  at  its 
extremities,  so  that  the  tensions  of  any  two  transverse  interfaces  of 
the  string  must  be  the  same.  For  this  reason  we  often  speak  of  the 
tension  of  the  string  as  a  whole,  without  specifying  any  particular 
portion  of  it,  and  also  the  tension  between  the  two  bodies,  without 
considering  the  nature  of  the  string  through  which  the  tension  is 
exerted." 

The  string  or  its  equivalent  is  the  absolute  sine  qua 
non  of  a  Maxwellian  tension. 

On  page  78  he  clearly  distinguishes  between  a  stress, 
such  as  the  tension  of  a  rope,  or,  on  the  other  hand,  a 
pressure  from  without.  On  the  same  page  he  says : 

"The  stress  is  measured  numerically  by  the  force  exerted  on 
either  of  the  two  portions  of  matter  [e.g,  the  sun  and  the  earth]. 
It  is  distinguished  as  a  tension  when  the  force  acting  on  either  por- 
tion is  toward  the  other  [that  is,  from  within],  and  as  a  pressure 
when  the  force  acting  on  either  portion  is  away  from  the  other 
[that  is,  from  without]." 

We  could  quote  much  more  to  the  same  effect. 

Tension,  as  I  have  repeatedly  stated,  is  predicable 
only  of  a  material  bond  rendered  tense  by  a  force  tend- 
ing to  pull  it  asunder  or  separate  its  transverse  inter- 
faces. I  need  not  argue  that  the  ether,  the  only  medium 
extending  from  the  sun  to  the  earth,  is  incapable  of  be- 
ing twisted  into  ropes  or  cables,  capable  of  sustaining  a 
longitudinal  tension  or  strain.  If  not,  then  the  only 
other  method,  according  to  Maxwell,  is  a  pressure  from 
opposite  directions.  On  page  130  he  says : 

"We  may  in  general  avoid  any  ambiguity  by  viewing  the  phe- 
nomenon as  a  whole,  and  speaking  of  it  as  stress  exerted  between 


STRESS STRAIN TENSION.  1 69 

two  points  or  bodies,  and  distinguishing  it  as  a  tension  or  a  pressure, 
an  attraction  or  a  repulsion,  according  to  its  direction." 

These  quotations  from  Maxwell  are  much  more 
significant  than  if  they  had  been  applied  by  him  to 
the  subject  of  gravitation,  as  they  are  the  necessary 
laws  of  physical  forces,  deduced  from  pure  mathe- 
matical reasoning.  The  laws  of  motion  are  the  same 
for  large  bodies  as  for  small,  and  for  long  distances 
as  for  short;  the  same  for  suns  and  planets  in  the 
heavens  as  for  marbles  on  the  floor.  How  can  two 
bodies  be  made  to  approach  each  other  on  the  earth? 
It  must  be  by  a  pressure  on  one  or  both  from  without  or 
by  a  pull  exerted  between  the  bodies,  or  as  Maxwell 
expresses  it,  "a  pressure  or  a  tension."  If  a  pressure, 
it  must  be  applied  through  some  form  of  matter  in  mo- 
tion, as  by  two  hands  on  the  opposite  sides  of  two  balls. 
If  a  tension,  it  must  be  exerted  through  a  material  bond 
capable  of  sustaining  a  longitudinal  strain. 

We  are  therefore  compelled  by  the  inexorable  logic 
of  mathematical  reasoning  to  conclude  that  the  earth 
and  sun  approach  each  other  by  a  "pressure"  from 
without  and  not  by  a  "tension"  produced  by  attraction 
from  within.  The  existence  of  chemical,  cohesive  and 
capillary  attraction  offers  no  objection  to  this  theory,  as 
they  do  not  act  at  a  distance  and  do  not  involve  the  ex- 
istence of  any  connecting  bond.  As  to  electrical  and 
magnetic  attractions,  they  also  act  only  at  short  distances, 
and  are  in  no  sense  analogous  to  gravity,  which  acts  at 
distances  of  hundreds  and  thousands  of  millions  of 
miles.  It  is,  however,  just  as  easy  to  explain  electrical 
and  magnetic  attractions  by  a  pressure  of  ethereal  waves 
from  without,  as  by  the  contraction  of  any  supposed 
bond  between  bodies  thus  affected. 


170  GRAVITATION. 

I  will  close  this  chapter  with  this  summation.  One 
thing  is  certain  :  Gravitation  is  a  fact.  Another,  equally 
certain,  is  that  it  is  a  real  force  impelling  the  earth  to- 
ward the  sim  and  the  sun  toward  the  earth. 

A  third  certainty  is  that  this  force  is,  in  the  language 
of  Maxwell,  in  the  nature  of  a  "  pressure  or  a  tension." 

It  is  true  in  the  fourth  place  that  if  this  force  be  in 
the  form  of  a  tension,  it  must  be  exerted  through  a 
medium  capable  of  sustaining  a  tension  caused  by  a 
longitudinal  stress. 

In  the  fifth  place,  there  can,  of  course,  be  no  medium 
but  the  ether,  and  we  can  no  more  conceive  of  ether  as 
capable  of  sustaining  a  longitudinal  tension,  than  we 
could  expect  the  same  from  free  and  unconfined  gases. 

Finally,  such  a  force  could  have  no  relation  to  gravi- 
tation. Gravitation  follows  the  law  of  the  inverse 
squares,  which  is  the  law  of  all  forms  of  radiant  energy 
propagated  by  ethereal  vibrations.  None  but  radial 
action  observes  strictly  this  law.  This  seems  to  close 
the  gap  and  make  it  absolutely  certain  that  gravitation 
is  a  force  propagated  through  the  ever  widening  waves 
of  the  ether,  which  are  always  propulsive  and  outward 
from  their  sources ;  which  always  come  from  material 
senders ;  which,  in  the  case  of  gravitation,  can  be  no 
other  than  the  starry  hosts. 

It  seems  certain,  therefore,  that  gravitation  is  effected 
through  a  pressure  and  not  a  tension ;  a  push  instead  of 
a  pull. 


CHAPTEK    XIII. 

THE  CAVENDISH  EXPERIMENT. 
In  nice  bcilance  poised. — POPE. 

THIS  experiment  in  its  simplest  form  may  be  per- 
formed by  means  of  one  pair  of  balls,  as  large  as 
practicable,  of  lead  or  iron,  a  and  5,  upon  the  ends  of  a 
swinging  table  or  plank,  and  another  pair,  a'  and  &',  sus- 
pended by  a  fine  thread  or  wire  and  brought  \vithin  a 
short  distance  of  the  former.  This  second  pair  may  be 
of  any  convenient  size,  but  it  is  well  to  have  them  small 
enough  so  as  not  to  strain  unduly  a  fine  silk  thread  by 
which  they  are  suspended.  The  following  figure  illus- 
trates the  experiment  as  seen  from  a  position  between 
the  horizontal  and  perpendicular. 


172 


GRAVITATION. 


The  experiment  can  be  performed  in  the  open  air  of 
a  still  room,  but  better  in  a  close  cabinet  with  glass  sides, 
and  better  still  in  an  exhausted  receiver,  if  this  were 
practicable,  in  order  to  exclude  all  disturbing  atmos- 
pheric currents  and  resistance.  It  is  found  by  careful 
observation  that  the  balls  a  and  a'  and  also  l>  and  b' 
will  approach  each  other  with  a  perceptible,  but  very 
slow  and  feeble  motion  until  arrested  by  the  torsion  of 
the  thread,  precisely  similar  to  gravitation  between 
larger  bodies,  and  governed  by  exactly  the  same  laws. 
A  modified  figure  will  better  illustrate  our  idea. 

o 


Hemisphere  of  the  Earth 


FIG.  7. 


Here  we  have  a  genuine  case  of  gravitation  right 
under  our  eyes,  and  I  am  sure  we  can  study  it  with 
interest  and  perhaps  with  profit. 

Here  is  a  force  at  work  either  pushing  or  pulling 


THE  CAVENDISH  EXPERIMENT.          173 

these  halls  together.  As  J.  Clerk  Maxwell  has  shown, 
this  force  must  be  either  a  "  pressure  "  or  a  u  tension." 
If  a  "  pressure,"  it  must  be  applied  from  the  outside  in 
the  direction  of  the  arrows,  and  some  veritable  material 
substance  must  actually  press  upon  the  balls,  for  there 
can  be  no  pressure  without  something  to  press.  If  on 
the  contrary  it  is  a  "  tension,"  then  there  must  be 
an  actual  material  bond  between  the  balls  capable  of 
becoming  tense  by  being  pulled  upon  by  the  balls 
respectively.  The  quality  of  tension  cannot  exist  in 
the  absence  of  the  subject  of  that  quality.  What 
could  our  college  boys  do  in  the  game  called  the  "  tug 
of  war  "  without  a  rope  to  pull  on  ? 

Not  only  must  there  be  on  this  theory  a  string  or 
material  bond  between  the  balls,  but  that  string  must 
actually  be  wound  up  as  by  a  windlass  or  shortened 
at  both  ends,  or,  rather,  through  its  entire  length,  for 
we  see  with  our  eyes  the  balls  visibly  approaching  each 
other. 

But  whether  the  balls  approach  each  other  by  a 
"  pressure  "  or  by  a  u  tension,"  the  material  medium  in 
either  case  is  the  invisible  ether,  for  if  performed  in 
a  vacuum  the  air  is  excluded,  and  nothing,  so  far  as  we 
know  or  believe,  is  left  but  the  intangible  and  invisible 
ether.  This  ether  is  the  most  tenuous  form  of  matter  ; 
and  its  sole  function,  so  far  as  we  know,  is  to  be  the  me- 
dium through  which  are  propagated  the  undulations  of 
light,  heat,  mechanical  motion,  and  other  forms  of 
energy.  But  all  these  undulations  proceed  from  mate- 
rial senders  to  material  receivers. 

By  recurring  to  the  last  figure,  it  is  easy  to  see  how 
beautifully  the  Cavendish  experiment  illustrates  the 
theory  of  gravitation  by  propulsive  undulations.  The 


174  GRAVITATION. 

waves,  coming  in  all  directions  from  the  starry  concave, 
impinge  on  all  sides  of  the  balls  except  where  one  ball 
intercepts  them  from  the  other;  and  both  balls  will 
necessarily  move  in  the  direction  of  the  least  resistance, 
that  is,  toward  each  other.  These  undulations  are  not 
hypothetical  but  actual  by  the  consensus  of  all  philoso- 
phers. In  order  to  produce  the  effect  we  call  gravity, 
they  have  only  to  act  according  to  necessary  mathe- 
matical laws. 

But  let  us  suppose  this  same  ether  to  attempt  to 
bring  these  balls  together  by  means  of  a  u  tension." 
Can  ether  form  itself  into  a  rope  capable  of  resisting  a 
strain  tending  to  separate  what  Maxwell  calls  its 
"  transverse  interfaces  "  ?  If  such  a  rope  were  formed 
could  it  contract  upon  itself  until  it  absolutely  disap- 
pears in  nonentity,  the  two  ends  telescoping  and  swal- 
lowing each  other  ?  Yet  this  must  be  so  on  this  theory, 
because  the  balls  approach  each  other  until  they  come 
in  contact  and  the  bond,  if  any,  is  annihilated. 

But  cannot  a  vibratory  motion  proceed  from  the 
balls  themselves  and  thus  produce  an  effect  upon  each 
other?  Most  undoubtedly,  for  all  bodies,  large  and 
small,  hot  and  cold,  in  fact  every  molecule  of  matter, 
are  in  a  constant  state  of  vibration.  But  these  vibra- 
tions are  outward  from  the  senders  to  the  receivers,  and 
tend  to  repel,  instead  of  bringing  the  balls  together. 
Being  infinitesimal  in  this  case,  their  effect  is  inap- 
preciable. To  sum  up : 

There  is  certainly  no  visible  medium  uniting  the 
different  pairs  of  balls,  capable  of  contracting  and  of 
being  the  subject  of  a  tension.  But  two  bodies  cannot 
approach,  or  tend  to  approach,  each  other  except  by  a 


THE    CAVENDISH    EXPERIMENT.  175 

"  pressure  "  from  without  or  a  "  tension  "  from  within, 
in  either  case  acting  through  a  material  medium. 

We  fail  utterly  to  find  a  contracting  medium  be- 
tween the  pairs  recoiling  upon  itself  and  exerting  a 
self -consuming  force. 

How  about  a  force  from  without  capable  of  exerting 
a  pressure  impelling  the  balls  together  ?  We  answer  : 

If  all  the  bodies,  dark  or  luminous,  that  people  the 
"profundities  of  space,"  were  visible  as  if  projected  in- 
wardly upon  a  hollow  celestial  sphere  at  the  distance  of 
the  nearest  fixed  stars,  there  would  probably  not  be  the 
space  of  a  needle  point  unoccupied  by  the  swift  flying 
messengers  of  omnipotence  shedding  effluence  from 
their  wings. 

This  effluence  proceeds  in  all  directions  in  straight 
lines  with  inconceivable  velocity,  and  impinging  on  the 
opposite  sides  of  the  balls  a  and  a ',  and  b  and  &',  impels 
them  together,  each  ball  intercepting  from  its  fellow  a 
portion  of  the  otherwise  neutralizing  waves  that  come 
from  the  opposite  direction. 

These  waves  are  not  mere  matters  of  moonshine, 
though  moonshine  itself  is  a  form  of  energy.  We  can- 
not turn  our  eyes  to  a  single  point  in  the  heavens, 
whether  by  sunlight,  by  moonlight,  or  by  starlight,  from 
which  light,  heat  and  mechanical  force  are  not  eman- 
ating. Even  in  the  blackest  Cimmerian  darkness,  when 
sleep  and  silence  enwrap  half  the  world,  the  waves  of 
mechanical  force  are  sleeplessly  doing  their  appointed 
work,  guiding  the  earth  in  its  pathway  to  meet  the 
morning  light. 

"  O,  Lord  !  how  manifold  are  thy  works.  In  wisdom 
hast  thou  made  them  all." 


CHAPTER    XIY. 

ILLUSTRATION    FROM    EXPERIMENTS    IN    DIFFEREN- 
TIAL GRAVITATION  BY  DRS.  KONIG  AND  RICHARZ. 

And  fast  by,  hanging  in  a  golden  chain, 
This  pendant  world,  in  bigness  as  a  star 
Of  smallest  magnitude.  — MILTON. 

AT  the  present  time  it  is  understood  that  Drs.  A. 
-^L\-  Konig  and  F.  Richarz  are  conducting  experiments 
at  Berlin  for  the  purpose  of  more  accurately  determining 
the  mean  density  of  the  earth ;  and  their  method  can 
just  as  well  be  utilized  for  a  very  different  purpose — 
that  of  illustrating  the  nature  of  gravitative  action. 

For  this  purpose  they  employ  a  block  of  lead,  H,  I, 
K,  L,  weighing  100,000  kilos  or  125  tons.  Let  A,  B,  C, 
represent  a  delicate  balance  with  scales  both  above  and 
below  the  cubical  block  of  lead  and  connected  by  wires 
passing  through  perforations  in  the  block.  These 
learned  gentlemen  of  course  treat  of  gravitation  as  a 
force  of  attraction  residing  in  matter,  and  the  experi- 
ments are  made  to  show  the  difference  in  the  so  called 
attraction  upon  weights  situated  above  and  below  this 
ponderous  block  of  lead.  Thus :  let  a  weight  be  placed 
in  scale  D  above,  and  an  equal  one  in  scale  G  below  the 
block.  It  will  be  found  that  D  will  go  down  and  G 
will  go  up,  because,  as  is  said,  D  is  attracted  by  both 
the  earth  and  the  block,  while  G  is  attracted  by  the  ex- 

176 


EXPERIMENTS   BY    DRS.    KONIO   AND    RICHARZ.        177 


cess  only  of  the  earth's  attraction  over  that  of  the  block, 
whose  attraction  is  in  the  opposite  direction. 

This  experiment  may  be  varied  by  reversing  and 
exchanging  the  weights,  but  the  result  is  always  in 
accordance  with  the  above,  mutatis  mutandis. 


H 


K 


\L 


FIG.  8. 

The  lesson  to  be  learned  from  this  experiment  is 
already  a  thrice  told  tale.     But,  like  the  Cavendish  ex- 
periment, this  one  brings  the  grand  force  of  gravitation 
down  from  the  heavens,  and  exhibits  it  immediately 
12 


178  GRAVITATION. 

under  our  eyes ;  and  the  close  quarters  in  which  it  is  for 
the  time  corralled  help  our  minds  to  grasp  the  subject. 

With  the  figure  before  our  eves,  let  us  see  if  we  can 
form  an  intelligent  and  unprejudiced  opinion  as  to 
whether  this  force  is  in  the  nature  of  a  push  or  a  pull. 

That  every  particle  in  nature  is  capable  of  receiving 
and  transmitting  vibratory  motions  of  various  kinds, 
but  not  of  inaugurating  them,  is  a  fundamental  fact  in 
physics.  Some  of  these  vibrations,  as  those  of  light  and 
electricity,  can  act  through  media  as  hard  as  diamond 
and  steel,  and  almost  as  dense  as  lead.  It  is  surely  not 
a  violent  supposition  that  others,  as  mechanical  force, 
can  act  through  a  block  of  lead,  especially  after  proof 
positive  of  the  fact. 

The  block,  H,  I,  K,  L,  rests  by  props  or  posts  upon 
the  earth,  forms  a  part  of  the  earth,  and  adds  nothing 
to  the  so  called  attraction  of  the  earth  as  a  whole.  But 
when  separated  by  a  short  distance  from  the  remainder 
of  the  earth,  it  can  be  made  to  antagonize  the  so  called 
attraction  of  this  remainder  to  an  appreciable  extent. 

Let  us  now  suppose  the  weight  D  to  be  the  centre  of 
impinging  propulsive  waves  (not  hypothetical,  but  ac- 
tual, as  I  have  shown  by  abundant  quotations)  from  all 
possible  directions  except  where  intercepted.  It  is  evi- 
dent that  almost  all  the  waves  from  the  direction  of  the 
earth,  including  the  block  as  a  part  of  it,  will  be  inter- 
cepted from  the  weight  D,  and  it  will  gravitate  strongly 
toward  the  earth.  It  is  equally  evident  that  from  the 
weight  G  a  very  small  portion  of  the  waves  from  the 
opposite  direction  (interceptions  being  always  in  propor- 
tion to  mass)  wrill  be  intercepted  by  the  block,  and  so 
the  weight  G,  suspended  between  two  intercepting 
masses,  will  gravitate  writh  slightly  less  force  than  D. 


EXPERIMENTS    BY    DRS.    KONIG    AND    RICHARZ.        179 

The  particles  composing  the  earth  cannot  reach  up 
through  the  hole  in  the  block,  nor  through  the  lead,  nor 
around  it,  to  grasp  the  weight  D  to  pull  it  down,  be- 
cause they  possess  no  tentacles,  or  arms,  with  which  to 
reach  out  even  to  short  distances,  much  less  to  the  con- 
fines of  creation.  If  every  particle  possessed  as  many 
arms  as  Briareus,  multiplied  by  millions,  they  could  not 
employ  one  of  them,  because  the  particles  are  absolutely 
inert.  Maxwell  and  others  have  shown  that  a  pull  can 
be  exerted  only  through  a  string  or  connecting  bond; 
and  Stallo,  backed  by  an  indefinite  number  of  authori- 
ties, Newton,  included,  boldly  asserts  that  "  there  are  in 
nature  no  pulls,  but  only  thrusts." 

I  need  not  repeat  all  the  quotations  I  have  hereto- 
fore made  from  Newton,  Maxwell,  Daniels,  Stallo, 
Challis,  Croll,  Secclii,  Mohr,  Du  Bois  Reymoiid,  Bal- 
four  Stewart,  and  P.  G.  Tait,  to  the  effect  that  all 
physical  force  is  exerted  propulsively  by  impact,  direct 
or  through  some  intervening  medium.  I  might  also 
have  quoted  from  Huygens,  Leibnitz,  Bernouilly,  Euler, 
and  many  others  to  the  same  effect.  I  will  not  again 
appeal  to  the  reason  of  the  reader,  which  will  tell  him, 
as  it  told  Newton,  that  the  very  idea  of  action  at  a  dis- 
tance, without  an  intervening  medium,  is  inconceivable. 
I  will,  however,  quote  one  more  sentence  from  New- 
ton's third  letter  to  Bentley : 

"It  is  inconceivable  that  inanimate  brute  [inert]  matter  should, 
without  the  mediation  of  something  else  which  is  not  material  [i.e., 
without  an  ethereal  medium],  operate  upon  and  affect  other  mat- 
ter, without  material  contact,  as  it  must  do  if  gravitation,  in  the 
sense  of  Epicurus,  be  essential  and  inherent  in  it.  And  this  is  the 
reason  why  I  desired  you  would  not  ascribe  innate  gravity  to  me." 

Although  writers  of  the  highest  scientific  attainments 


180  GRAVITATION. 

constantly,  though  thoughtlessly,  speak  of  gravity  as  in- 
nate and  inherent  in  the  particles  of  matter,  still  I 
know  of  none  who  will  answer  affirmatively  the  ques- 
tion when  independently  propounded  — "  Can  matter 
act  upon  other  matter  at  a  distance,  without  an  inter- 
vening medium?"  Nor  do  I  know  of  any  wrho  will 
squarely  take  issue  with  Newton  and  the  other  distin- 
guished scientists  just  named,  that  all  force  is  exerted 
propulsively  by  actual  impact ;  that  is,  by  one  particle 
or  mass  bumping  or  pushing  against  another.  But  if 
all  force  is  propulsive,  gravitation  can  be  no  exception, 
and  the  earth  and  planets  are  pushed  and  not  pulled  to- 
ward the  sun.  If  they  are  pushed  toward  the  sun  there 
must  be  an  inconceivable  number  of  bodies  engaged  in 
making  these  pushes,  for  these  are  from  all  possible  di- 
rections. The  pushing  bodies  must  also  be  located  at 
immense  distances.  If  they  were  arranged  around  our 
solar  system  just  outside  of  the  planetary  orbits,  they 
would  fill  a  hollow  sphere  around  the  solar  system  solid 
and  shut  out  from  us  the  light  of  the  fixed  stars,  as 
gravitation  streams,  so  to  speak,  from  every  point  in  the 
heavens. 

Besides,  every  other  sun,  having  a  system  of  revolv- 
ing planets,  would  need  a  similar  hollow  sphere  to  fur- 
nish the  force  of  gravitation  for  its  included  planets, 
But  these  are  totally  unnecessary.  We  have,  ready 
formed  and  planted  in  space,  extending  to  infinity  in  all 
directions,  solar  bodies  with  their  attendant  orbs,  which 
not  only  can,  but  actually  do,  act  as  both  senders  and 
receivers  of  waves  of  mechanical  force.*  These,  if 
they  could  all  be  projected  inward  till  they  met  our  vis- 
ion, would  doubtless  form  an  apparent  hollow  sphere  of 

*  See  authorities  quoted  from  Judge  Stallo's  pages. 


EXPERIMENTS    BY    DES.    KONIG    AND    RICHAEZ.        181 

suns  of  unknown  depth  around  our  sun,  and  the  same 
would  be  true  of  every  other  sun.  Though  a  billionth 
part  of  the  emanations  from  many  of  these  suns  may 
never  reach  ours,  still  none  of  them  will  be  lost.  They 
will  advance  endlessly,  riding  on  the  wave  crests  of 
ether,  until  they  impinge  on  some  of  the  suns  or  worlds 
that  people  the  "  profundities  of  space."  There  are 
absolutely  no  sources  in  nature  except  the  innumerable 
denizens  of  space,  from  which  these  pushes  can  proceed, 
and  no  medium,  so  far  as  we  know,  through  which  these 
impulses  can  be  propagated,  except  the  universal  ether. 
As  every  exercise  of  energy  involves  exhaustion,  pro 
tanto,  every  one  of  the  celestial  bodies  which  are  send- 
ing forth  the  impulses  of  gravitation  and  other  forms  of 
energy,  light  and  heat  included,  must  at  the  same  time 
be  receiving  equal  reinforcements  from  the  same  sources ; 
and  thus  the  universal  equilibrium  is  maintained,  and 
all  the  energies  of  nature  are  conserved. 


CHAPTER  XY. 

REDUCTIOXES  AD  ABSURDA. 

Our  readers  are  no  doubt  familiar  with  a  method  which  Euclid 
frequently  adopts  in  proving  his  propositions.  Starting  with  the 
supposition  that  they  are  not  true,  and  reasoning  upon  this  hypothe- 
sis, he  comes  to  an  absurd  conclusion  —  hence  he  concludes  they  are 
true. —  BALFOUR  STEWART. 

L3GIC,  or  correct  reasoning  from  known  premises, 
lias  no  wider  nor  more  legitimate  Held  for  its  ex- 
ercise than  in  the  domain  of  physics. 

That  which  is  shown  to  be  absurd,  in  the  sense  of 
the  impossible,  by  sound  reasoning  from  admitted  facts, 
cannot  be  true. 

Let  us  examine  a  few  of  the  consequences  that  would 
follow  the  assumption  of  the  truth  of  the  traction  theory 
of  gravitation. 

1.  If  this  theory  were  true,  then  the  energy  in  action, 
or  force  which  impels  the  earth  toward  the  sun,  origi- 
nates in  the  molecules  composing  the  sun.     No  advo- 
cate of  this  theory  goes  beyond  the  sun  in  search  of 
the  force  supposed  to  be  exerted  by  him  on  the  earth. 
But  it  is  an  axiom  in  physics  that  energy  originates  no- 
wrhere,  but  is  simply  communicated  from  one  body  to 
another  in  endless  succession. 

2.  According  to  the  traction  theory,  this  force  un- 
dergoes no  exhaustion  by  its  exercise,  for  it  never  ceases 
to  act,  and  by  the  supposition  has  no  source  beyond  the 
sun  to  draw  upon. 


REDUCTIONES   AD   ABSURD  A.  183 

But  it  is  an  axiom  in  physics  that  no  work  can  be 
done  by  any  force  without  corresponding  exhaustion, 
either  of  heat  or  of  some  other  form  of  energy. 

3.  According  to  this  theory,  the  work  of  impelling 
the  earth  toward  the  sun  is  by  traction  instead  of  pro- 
pulsion, and  Newton's  dictum  that  all  force  is  "  vis  a 
tergo "  or  propulsive,  and  all  the  affirmations  of  it  by 
the  eminent  scholars  before  quoted,  fall  to  the  ground. 

4.  Again,  this  supposed  pulling  force,  if  such  exists, 
must,  of  course,  be  exerted  through  the  medium  of  the 
ether,  as  there  is  no  other  medium.     We  have  often 
heard  of  a  rope  of  sand,  but  no  one  has  yet  ventured  to 
suggest  a  rope  of  ether  capable  of  sustaining  a  longi- 
tudinal tension. 

5.  Upon  the  traction  theory,  the  earth  and  sun  mu- 
tually pull  upon  each  other  as  the  objects  respectively 
of  the  force  exerted  by  each  through  the  connecting 
medium.     Now,  whatever  be  the  nature  of  a  medium 
capable  of  sustaining  a  longitudinal  tension,  the  stress  is 
equal  on  all  "  its  transverse  interfaces,"  that  is,  the  force 
would  be  equal  at  every  point  between  the  sun  and 
the  earth.     (See  Maxwell's  "  Matter  and  Motion,"  Van 
Nostrand  Edition,  page  79.) 

But  the  fact  is,  the  force  of  gravitation  exercised  by 
the  sun  is  greatest  at  his  surface  and  diminishes  out- 
wardly with  great  rapidity.  So  of  the  earth.  The 
gravitation  exercised  by  each  may  be  compared  to  a 
sharply  tapering  truncated  cone. 

6.  It  is  now  regarded  as  axiomatic  that  all  energy  is 
conserved,  that  is,  it  does  not  die  when  once  exerted, 
but  passes  on  from  one  body  to  another  forever.     But 
according  to  the  traction  theory,  gravitation  is  without 
successor  as  well  as  without  predecessor.     It  proceeds  no 


184  GRAVITATION. 

farther.  It  dies  a  natural  death  so  soon  as  it  is  exerted, 
and  the  earth  and  sun  are  required  to  put  forth  new 
impulses  every  moment  from  their  own  inherent  re- 
sources. 

I  have  stated  the  above  principles  in  the  briefest 
possible  form,  as  they  are  too  familiar  to  all  students  of 
physics  to  require  amplification. 

The  propulsion  theory,  on  the  contrary,  avoids  every 
one  of  these  reductiones  ad  absurda,  thus : 

1.  The  force  of  gravitation  is  not  originated  in  the 
earth  or  sun,  but  forms  a  link  in  an  endless  chain  of 
action  and  reaction. 

2.  According  to  this  theory,  every  molecule   con- 
cerned is  both  exhausted  of  its  mechanical  motion,  and 
at  the  same  time  resupplied.     They  are  all  senders  and 
all  receivers,  and  operate  in  endless  cycles. 

3.  This  theory  gives  effect  to,  instead  of  nullifying, 
Newton's  dictum,  that  all  force  is  propulsive. 

4.  This  theory  employs  the  ether  according  to  its 
true  nature,  as  the   bearer  of  propulsive   vibrations, 
instead  of  requiring  of  it  a  function  of   longitudinal 
tension,  to  which  it  is  in  no  wise  adapted. 

5.  According  to  this  theory,  the  force,  instead  of 
being  equal  at  every  point,  would  diminish  in  quantity 
in  each  direction  in  the  ratio  of  the  inverse  squares, 
which  is  the  fact. 

6.  This  theory  conserves  the  whole  of  the  energy 
employed.     It  comes  from  every  one  of  the  celestial 
bodies,  and  after  performing  the  functions  required  of 
it,  in  one  solar  family,  takes  wing  for  other  suns  and 
systems  "  in  modum perpetuum" 


CHAPTEE  XVI. 

CIRCUMSTANCES    UNDER  WHICH    HEAT    CHANGES    TO 
MECHANICAL  FORCE  AND  OTHER  FORMS  OF 
ENERGY,  AND  VICE  VERSA  — META- 
MORPHOSIS OF  MOTION. 

See  all  things  with  each  other  blending, 

Each  to  all  its  being  lending, 

Each  on  all  in  turn  depending; 

Heavenly  ministers  descending, 

Arid  again  to  Heaven  uptending, 

Floating,  mingling,  interweaving, 

Rising,  sinking,  and  receiving.  —  GOETHE. 

HEAT,  especially  in  its  higher  degrees,  seems  not 
only  ready,  but  impatient,  to  assume  the  form  of 
mechanical  motion.  For  example,  heated  steam,  heated 
air  —  in  fact,  every  heated  substance  —  seeks  to  ex- 
change its  heat  for  mechanical  or  molar  motion.  In 
fact,  heat  only  retains  this  form  in  virtue  of  the  matter 
in  which  it  resides  being  hemmed  in,  compressed,  or  in 
some  way  prevented  from  freely  expanding.  This  ten- 
dency of  heated  matter  to  burst  its  bounds  is  generally 
in  proportion  to  the  degree  of  heat.  This  heat  neces- 
sarily seeks  vent  in  the  direction  of  the  least  resistance. 
The  wonderful  ingenuity  of  man  is  largely  employed 
in  devising  useful  and  curious  modes  of  letting  down 
the  high  tension  energy  of  heat  to  the  lower  levels  of 
mechanical  motion. 

If  we  may  be  allowed  to  describe  in  figurative  lan- 
guage, the  condition  of  matter  in  the  nebulous  state,  we 

185 


186  GRAVITATION. 

would  say  that  it  was  longing  for  rest  in  the  form  of 
molar  action  as  a  relief  from  the  higher  tension  of  ther- 
mal vibration.  Or,  more  briefly;  heat  is  mainly  pent 
up  mechanical  motion,  seeking  vent.  This  it  finds  first 
in  vortical  motion. 

But  this  is  not  the  only  mode  of  relief  from  intense 
heat.  When  matter  has  begun  to  separate  its  denser 
from  its  rarer  forms,  leaving  pure  ether  to  occupy  the 
space  alone,  formerly  occupied  by  a  mixture  of  all  kinds 
of  matter,  then  heat  finds  vent  in  sending  its  thermal 
vibrations  on  long  journeys,  in  the  course  of  which  they 
ultimately,  in  accordance  with  fixed  laws,  assume  the 
form  of  mechanical  vibrations,  including  gravitation. 

A  third  form  of  energy  comes  to  light  when  heat 
has  so  far  moderated  its  intensity  as  to  admit  of  chemi- 
cal affinity,  which  opens  a  new  and  broad  field  for  the 
exercise  of  energy  in  a  modified  form. 

A  fourth  ferm  following  in  order  is  cohesive  attrac- 
tion. 

The  latest  to  appear  are  electricity  and  magnetism, 
streams  from  the  same  fountain. 

It  is  a  facilis  descensus,  and  is  readily  appreciated. 
It  is  going  on  wherever  heat  exists,  and  on  the  largest 
scale  where  heat  is  most  abundant,  viz. :  in  all  the 
solar  bodies.  Heat  is  always  and  everywhere  seek- 
ing relief  from  the  high  tension  of  that  condition  of 
matter. 

This  tendency,  if  uncounteracted,  could  only  result 
in  universal  diffusion  and  equality.  Should  this  condi- 
tion take  place,  all  motion  and  all  life  would  cease,  for 
the  fluctuations  of  heat  are  the  cause  of  both.  This 
inherent  and  ineradicable  tendency  of  heat  to  equaliza- 
tion and  a  dead  level  was  coeval  with  matter,  and  has 


CIRCUMSTANCES    UNDER    WHICH    HEAT    CHANGES.     187 

attended  it  through  all  the  ages  of  its  existence ;  and  if 
uncounteracted,  must  long  ago  have  resulted  in  univer- 
sal equality,  universal  stagnation,  and  universal  death. 

Where  there  is  confessedly  so  much  "  running  down  " 
of  nature's  machine,  there  must  of  necessity  be  a  corre- 
sponding winding  up  of  the  same.  Where  there  is  so 
much  diffusion,  there  must  be  a  corresponding  recon- 
centration. 

This  winding  up  of  the  machinery  of  the  universe  or 
reconcentration  of  its  energies  is  not  effected  by  miracle, 
but  by  these  energies  acting  according  to  fixed  laws. 
There  is  no  difficulty  in  conceiving  of  nature  as  a  "  per- 
petual  motion."  In  fact  we  cannot  conceive  of  it  other- 
,wise.  The  most  imperfect  machine  of  human  invention, 
or  even  a  ball  set  in  motion,  would  be  a  perpetual  mo- 
tion, if  only  all  the  motion  first  communicated  to  it 
could  be  confined  to  it. 

We  shall  therefore  not  be  surprised  to  find  that, 
great  as  seems  to  be  the  tendency  of  heat  to  change  to 
mechanical  motion  and  other  forms  of  energy,  the  ten- 
dency is  equally  great  to  change  back  in  a  "  perpetual 
motion." 

CIRCUMSTANCES  UNDER  WHICH  THE  DERIVATIVE  FORMS  OF 
ENERGY  RETURN  TO  THE  PRIMITIVE  FORM  OF  HEAT. 

1.  In  case  of  arrested  mechanical  motion,  as  when  a 
sledge  hammer  strikes  an  anvil,  or  a  cannon  ball  an 
iron  target  and,  instar  omnium,  if  I  am  correct,  when 
the  vibrations  of  mechanical  force  perform  the  double 
duty  of  supplying  the  force  of  gravitation  to  the  planets 
and  light  and  heat  to  the  sun. 

2.  By  means  of  friction,  as  illustrated  by  the  experi- 
ments of  Count  Rumford. 


188  GRAVITATION. 

3.  By  electricity,  when  obstructed  by  being  compelled 
to  pass  along  a  wire  of  inadequate  size,  or  through  any 
obstructive  medium. 

4.  By  chemical  combination,  where  the  components 
undergo  condensation,  or  occupy  smaller  space  after 
combination  than  before,  as  in  all  forms  of  oxidation 
and  combustion. 

All  these  processes,  by  means  of  which  the  deriva- 
tive forms  of  energy  revert  to  heat,  the  primitive  form, 
resolve  themselves  substantially  into  the  first,  viz.:  ar- 
rested, obstructed,  or  imprisoned  mechanical  motion. 

To  accomplish  any  of  these  retrograde  processes 
requires  a  clashing,  concussion  or  condensation  of  parti- 
cles forced  to  occupy  a  diminished  volume. 

But  in  the  reverse  process  of  heat  resolving  itself 
into  the  derivative  forms  of  motion,  nothing  is  necessary 
but  to  allow  the  matter  in  which  the  heat  resides  free 
scope  to  expand  ;  and  the  mutual  repulsion  of  the  parti- 
cles produces  expansion  and  lowering  of  temperature, 
finally  merging  into  mechanical  motion  and  other  forms 
of  energy. 

This  latter  process  seems  to  us  spontaneous  and  easy, 
while  the  reverse  seems  to  be  up-hill  work.  But  in 
nature,  all  changes  are  equally  easy  and  spontaneous 
under  the  proper  conditions. 

All  changes  in  nature  may  be  figured  as  a  series  of 
equations,  in  which  each  term  is  always  equal  to  both 
the  preceding  and  the  succeeding  ones ;  each  sustaining 
the  relation  of  effect  to  the  former  and  cause  to  the  lat- 
ter ;  or,  rather,  the  following  term  is  identical  with  the 
preceding,  but  sometimes  in  a  metamorphosed  form. 

There  can,  therefore,  be  neither  loss  nor  cessation  of 


CIRCUMSTANCES    UNDER    WHICH    HEAT    CHANGES.     189 

active  energy,  because  every  exercise  of  energy  perpetu- 
ates itself  entire  in  that  which  immediately  succeeds. 

We  are  mainly  concerned  with  two  forms  only  of 
motion  or  energy ;  the  general  one  of  heat,  and  the 
special  one  of  mechanical  force  ;  the  former,  on  account 
of  its  connection  with  the  sun;  the  latter,  on  account 
of  its  identity  with  gravitation.  I  have  used  these 
terms,  motion  and  energy,  interchangeably,  because  I 
believe  them  to  be  synonymous.  One  body  in  motion, 
by  impact  on  another,  causes  motion  in  that  other. 
What  we  call  energy  does  the  same  thing,  and  it  does 
nothing  more.  What,  then,  is  energy  but  matter  in 
motion  by  impact,  immediate  or  intermediate,  setting 
other  matter  in  motion? 

Let  us  now  inquire  a  little  more  fully,  under  what 
circumstances  one  of  these  forms  of  force  or  motion 
changes  to  the  other. 

And  first,  when  is  molar  or  mechanical  motion 
changed  to  heat  ?  I  reply :  When  it  cannot  help  itself, 
or  rather  when  the  continuance  of  this  form  of  motion 
is  more  difficult  than  some  other  form.  Thus,  when  a 
cannon  ball  is  stopped  by  an  iron  target  or  a  rock, 
further  motion  in  this  direction  is  rendered  impossible. 
But  as  motion  is  indestructible,  the  molar  motion  is 
changed  to  that  form  of  molecular  motion  most  easily 
assumed,  which  is  always  heat  in  cases  of  arrested  mo- 
tion. But  arrested  motion  is  only  one  form  of  com- 
pression or  enforced  condensation  of  matter. 

Wherever  compression,  especially  when  accompanied 
by  violence,  is  enforced  upon  any  form  of  matter,  heat 
or  general  molecular  vibration  is  the  result.  Thus,  in 
friction,  concussion,  collision,  compression,  in  short,  in 
every  case  where  matter  is  compelled  by  the  application 


190  GRAVITATION. 

of  external  force  to  occupy  diminished  space,  heat  is 
developed. 

But  under  what  circumstances  does  the  reverse 
change  —  the  change  from  heat  to  mechanical  force  — 
occur?  As  we  have  seen,  mechanical  force  changes  to 
the  general  or  mixed  vibrations  of  heat  under  the  influ- 
ence of  enforced  compression.  We  should  naturally 
expect  that  an  opposite  change  would  occur  under  op- 
posite circumstances,  and  we  shall  not  be  disappointed. 

The  opposite  circumstances  would,  of  course,  involve 
the  removal  of  all  forced  compression.  The  sudden  or 
gradual  removal  of  all  impediments  to  free  expansion 
in  all  directions  invariably  gives  rise  to  mechanical 
motion  in  compressed,  retarded,  or  arrested  bodies,  at 
the  expense  of  heat.  This  is  so  well  known  as  hardly 
to  require  illustration.  Compressed  steam  or  air  seeks 
to  take  on  the  form  of  mechanical  motion,  if  uncon- 
trolled, by  bursting  the  boiler.  If  controlled  by  human 
ingenuity,  and  let  down  to  the  lower  level  of  mechan- 
ical motion  by  a  system  of  valves,  pistons,  and  machin- 
ery, it  drives  our  railroad  trains,  mills,  and  factories. 

Now  for  its  application  to  the  subjects,  solar  heat 
and  gravitation.  The  mechanical  vibrations  of  ether 
are  never  fully  arrested  and  completely  stopped  until 
they  impinge  on  the  sun  and  other  solar  bodies.  At  the 
sun  a  peculiar  state  of  facts  exists.  The  sun  cannot  be 
moved  from  his  position,  as  the  earth  is,  by  gravitation, 
except  to  an  inappreciable  extent.  He  is  one  of  the 
centres  of  an  equal  bombardment  from  every  point  in 
the  heavens,  except  about  one  two  hundred  and  thirty 
millionth  part  intercepted  by  his  planetary  system. 
These  interceptions  are  confined  to  his  equatorial  re- 
gion, and  are  nearly  equal  from  all  parts  of  the  planet- 


CIRCUMSTANCES    UXDER    WHICH    HEAT    CHANGES.     191 

ary  belt,  so  that  he  is  always  kept  at  the  exact  gravita- 
tive  centre  of  his  system.  As  these  waves  of  mechan- 
ical force  cannot  be  employed  in  producing  a  modified 
translatory  motion  of  the  sun,  as  is  the  case  with  the 
earth,  they  must,  for  the  first  time  in  their  travels,  come 
to  a  full  stop,  and  heat  only  can  be  the  result.  There 
is  no  way  of  escape  open  to  the  heat  thus  generated, 
except  by  radiation.  The  photosphere  upon  which 
these  vibrations  fall  is  so  constituted  as  to  arrest  and 
absorb,  but  not  reflect,  these  waves.  What  amount  of 
heat  these  waves  of  mechanical  force  are  capable  of 
developing,  when  fully  stopped,  we  can  only  ascertain 
by  inquiry  at  the  sun. 

These  wave  motions  in  the  ether  are  now  at  their 
highest  tension  in  the  unspecialized  form  of  heat,  and 
located  at  the  greatest  radiator  of  heat  in  our  system, 
to  wit,  the  sun's  photosphere.  Radiated  from  this  sur- 
face, these  metamorphosed  vibrations  commence  an  al- 
most endless  series  of  propagations  through  the  sparsely 
inhabited  fields  of  ether.  Their  circumstances  are  now 
the  very  opposite  of  what  they  were  when  breaking 
upon  the  fiery  sides  of  fiercely  blazing  suns,  and,  of 
course  an  opposite  effect  may  be  expected.  By  this 
radiation  the  rays  find  room  for  divergence  and  expan- 
sion in  proportion  as  the  squares  of  the  distances  in- 
crease; and  they  will  gradually,  but  infallibly,  return 
to  the  form  of  vibrations  of  mechanical  force,  as  truly 
as  pent-up  steam  cools  by  expansion. 

The  principle  we  are  endeavoring  to  make  plain 
may  be  illustrated  in  varied  language,  thus :  When  any 
body,  solid,  liquid,  or  gaseous,  is  subjected  to  great  com- 
pression, either  by  forcing  it  to  occupy  smaller  space, 
or,  what  amounts  to  the  same  thing,  by  increasing  the 


192  GRAVITATION. 

tendency  to  expansion  without  increasing  the  space,  the 
pressure  communicates  itself  to  all  the  imprisoned 
molecules,  and  the  rise  in  temperature  will  be  in  pro- 
portion to  the  force  applied,  according  to  Daltoivs  law. 

Still  otherwise  expressed  :  Heat  is  the  result  of  a  great 
increment  of  motion,  in  proportion  to  volume,  concen- 
trated or  forced  upon  the  body  to  be  heated.  This  in- 
tense general  vibratory  motion,  constituting  heat,  drops 
back  spontaneously,  and  without  assistance,  to  the  deriv- 
ative forms,  simply  in  consequence  of  the  discontinu- 
ance of  the  disturbing  cause.  Thus,  the  specialized 
waves  that  roll  in  upon  the  sun  produce  an  inconceiva- 
ble pressure  upon  his  surface,  from  which  there  is  no 
escape,  as  they  come  from  all  directions,  and  the  sun's 
surface,  if  we  have  rightly  conceived  of  its  nature  as 
incandescent  carbon  clouds,  is  exactly  adapted  to  absorb, 
but  not  to  reflect  these  waves.  Their  accumulated  in- 
tensity can  therefore  only  find  vent  by  radiation  to  every 
nook  and  corner  of  creation. 

But  there  is  one  great  fact  that  must  never  be  forgot- 
ten ;  the  amount  of  energy,  in  whatever  form  arriving, 
must  be  exactly  equal  to  the  amount  leaving  the  sun. 
If  the  amount  arriving  were  greater,  the  sun  would  be 
growing  hotter ;  if  less,  the  sun  would  be  growing  colder ; 
but  neither  is  the  fact. 

The  strongest  objection  that  can  be  urged  to  this 
view,  is  the  fact  that  the  earth,  equally  with  the  sun,  is 
exposed  to  these  same  stellar  radiations,  but  becomes 
intensely  cold  instead  of  intensely  hot,  when  deprived 
of  other  sources  of  heat.  On  the  whole,  however,  the 
loss  of  heat  by  the  earth,  as  in  the  case  of  the  sun,  is 
equalled  by  arrivals  from  abroad  ;  and  in  both  cases,  the 
arrivals  and  departures  of  heat  are  through  the  sur- 


CIRCUMSTANCES    UNDER    WHICH    HEAT    CHANGES.     193 

rounding  ether.  In  both  the  temperature  remains  un- 
changed. The*  most  plausible  answer  that  can  be  made 
to  this  objection,  is  to  say  that  while  all  the  rays  of  me- 
chanical force,  and  perhaps  other  forms  of  energy,  cen- 
tring on  the  sun,  must  and  do  turn  to  heat,  and  that  in 
ample  quantities  to  supply  the  whole  vast  expenditure 
of  the  sun  by  radiation,  the  same  amount  of  stellar 
radiation  in  proportion  to  surface  reaching  the  earth,  is 
disposed  of  in  part  by  reflection,  in  part  by  gravitation, 
in  part  by  conversion  into  electricity  and  magnetism, 
and,  in  a  very  small  degree,  by  conversion  into  heat, 
thus  tempering  the  intense  cold  that  would  otherwise 
prevail  in  the  absence  of  the  sun. 

The  great  puzzle  is :  How  is  it  possible  for  the  cold 
vibrations  of  ether,  such  as  visit  our  earth  and  its  in- 
habitants by  night  as  well  as  by  day,  to  be  so  changed 
by  concussion  as  to  furnish  the  sum  total  of  the  heat 
radiated  by  the  sun,  by  simply  striking  the  solar  surface 
with  exactly  the  same  velocity  with  which  they  fall  on 
our  planet  ?  I  have  attempted  to  answer  this  question 
in  this  and  preceding  chapters,  but  further  illustrations, 
if  they  can  be  produced,  will  be  of  value. 

We  are  perfectly  safe  in  asserting  that  the  sun,  in- 
cluding his  atmosphere,  is  entirely  isolated  from  contact 
with  any  form  of  matter  except  ether.  Whatever  com- 
merce therefore  the  sun  carries  on  with  other  suns  or 
worlds  by  way  of  exchange  of  light,  heat,  gravitation 
or  other  forms  of  energy,  must  be  through  this  agency, 
which  acts  only  by  vibrations. 

We  know  he  is  sending  out  immense  quantities  of 
heat  through  this  medium  and,  by  reason  of  his  insulation, 
lie  can  receive  an  equivalent  only  through  the  same. 

We  have  already  referred  to  an  imaginary  atmos- 
13 


194  GRAVITATION. 

phere  of  oxygen  and  hydrocarbon,  and  to  the  Minneap- 
olis mills,  in  which  the  change  from  cold  to  hot,  on  a 
comparatively  small  scale,  is  almost  as  instantaneous 
and  wonderful  as  the  change  from  mechanical  to  heat 
vibrations  in  the  sun. 

But  there  is  another  class  of  phenomena  which  may 
illustrate  still  better  the  change  from  mechanical  to  heat 
vibrations  at  the  sun.  It  requires  a  sharp  blow,  and 
consequently  a  considerable  amount  of  arrested  motion, 
to  ignite  fulminating  powders  and  other  unstable  com- 
pounds, but  the  merest  touch  of  any  of  these  with  lire 
is  sufficient  to  ignite  them.  Though  travelling  at  the 
rate  of  eleven  and  a  half  million  miles  per  minute, 
the  waves  of  mechanical  force  have  not  sufficient  mo- 
mentum to  strike  fire  upon  a  cold  surface  like  the 
earth  ;  and  yet  we  may  easily  conceive  that  these  same 
waves,  falling  upon  the  already  superlatively  heated 
surface  of  the  sun,  may  change  to  waves  of  heat  by  a 
simple  change  in  the  kind  of  vibration,  without  increase 
in  amount,  and,  in  this  changed  form,  discharge  their 
whole  volume  upon  the  sun,  furnishing  him  with  ex- 
actly the  same  amount  of  heat  radiated  by  him  through 
the  same  medium. 

It  will  be  remembered  that  in  a  former  chapter  the 
writer  took  the  position  that  it  was  at  least  not  impossi- 
ble that  the  collisions  or  clashings  by  which  heat  is 
developed  at  the  sun  might  be  electrical,  without  in- 
dorsing it  unqualifiedly.  In  another  place  he  hints  the 
possibility  that  the  change  of  the  mechanical  waves  of 
ether  at  the  sun  was  due  to  an  induced  sympathetic 
vibration  in  harmony  with  those  existing  in  the  sun. 
These  are  simply  suggestions  of  specific  modes  of  trans- 
formation, for  the  consideration  of  the  learned.  The 


CIRCUMSTANCES    UNDER    WHICH    HEAT    CHANGES.     195 

present  chapter  only  alleges  generally  that  this  transfor- 
mation must  be  the  result  of  arrested  motion  of  some 
kind.  In  fact,  in  every  transformation  of  energy,  the 
preceding  form  must  be  arrested  before  the  succeeding 
one  can  appear. 


CHAPTEK   XVII. 

WHAT  IS  THE  ETHER  ? 

0,  thou  beautiful 
And  unimaginable  ether!  and 
Ye  multiplying  masses  of  increased 
And  still  increasing  lights!     What  are  ye?    What 
Is  this  blue  wilderness  of  interminable 
Air,  where  ye  roll  along,  as  I  have  seen 
The  leaves  along  the  limpid  streams  of  Eden? 
Is  your  course  measured  for  ye?    Or  do  ye 
Sweep  on  in  your  unbounded  revelry 
Through  an  aerial  universe  of  endless 
Expansion  —  at  which  my  soul  aches  to  think  — 
Intoxicated  with  eternity?  — BYRON. 

THE  nearest  approach  we  can  make  to  a  definition 
is  that  it  is  a  superlatively  tenuous  and  elastic 
fluid  under  a  high  state  of  compression  from  the  lack  of 
room  in  which  to  expand  itself,  though  it  has  all  space 
at  its  command.  This  being  its  normal  condition,  for 
which  we  are  not  bound  to  render  a  reason,  it  stands 
ready  to  respond  to  the  slightest  touch  of  any  arid 
every  motion  communicated  to  it  by  any  and  every 
kind  of  non-ethereal  matter. 

In  and  of  itself  it  is  in  a  state  of  perfect  equilibrium, 
there  being  nothing  to  prevent  the  universal  equaliza- 
tion of  the  pressure  of  the  particles  upon  each  other. 
It  can  therefore  start  no  vibrations  suo  motu,  and  all 
the  vibrations  of  which  this  ether  is  the  subject  must 
originate  proximately  from  non-ethereal  matter.  These 

196 


WHAT    IS    THE    ETHER?  197 

ethereal  vibrations  are  as  various  as  the  kinds,  forms 
and  conditions  of  the  matter  from  which  they  proceed. 
As  this  ether  is  in  a  state  of  equilibrium,  not  of  rest  but 
of  motion,  not  only  with  itself  but  with  all  other  matter, 
which  it  has  enveloped  from  eternity,  not  an  additional 
impulse  can  be  given  to  it  by  non-ethereal  matter,  but 
that  it  sends  forward  to  other  non-ethereal  matter  an 
equal  impulse,  so  that,  through  an  endless  series  of 
changes,  the  status  quo  of  both  is  preserved.  This 
ether  stands  ready  to  receive  every  impulse  of  heat, 
mechanical  motion,  and  every  other  form  of  motion, 
which  ordinary  matter  is  capable  of  communicating 
to  it,  and  bestows  the  same,  or  its  equivalent,  undimin- 
ished  upon  some  other  material  body  or  bodies.  Other- 
wise, it  might  be  filled  to  repletion,  and  drink  up,  so 
to  speak,  all  the  molecular  motions  of  all  non-ethereal 
matter,  and  nature  would  come  to  a  standstill.  This 
cannot  be  too  strongly  insisted  upon.  Nature  is  a  bal- 
anced machine  in  perpetual  motion.  Causes  are  con- 
stantly in  operation  tending  to  disturb  the  equilibrium, 
and  other  causes  are  as  constantly  in  operation  tending 
to  restore  the  equilibrium.  Thunder  storms,  tornadoes, 
cyclones,  earthquakes,  and  volcanoes  are  nature's  efforts 
to  restore  the  equilibrium  of  the  elements,  and  achieve 
calmness  and  quiet,  while  the  disturbing  causes  are 
molecular  motions  that  defy  detection  by  all  our  senses. 

The  vastness  of  the  ethereal  ocean,  being  co-extensive 
with  space,  is  no  impediment  to  the  performance  of  its 
functions,  but,  on  the  contrary,  it  furnishes  it  with  just 
the  verge  and  scope  these  functions  require ;  and  its 
perfect  elasticity  makes  it  as  ready  to  impart  as  to  re- 
ceive. Freely  it  receives,  and  freely  gives. 

We  now  stand  on  a  vantage  ground  from  which  we 


198  GRAVITATION. 

can  take  a  wonderfully  enlarged,  and  at  the  same  time 
time  wonderfully  simplified,  view  of  nature's  opera- 
tions. We  find  it  everywhere  laid  down  in  the  books 
that  the  disturbance  which  produces  light  and  heat  is  a 
mixture  of  all  kinds  of  ethereal  waves  or -vibrations. 
It  is  the  primal  and  unspecialized  form  of  universal 
energy.  It  was  the  sole  form  of  energy  extant  at  that 
remote  but  once  existent  period,  when  all  matter  was  in 
the  nebular  condition  from  inconceivable  heat.  The 
existing  suns,  that  stud  the  fields  of  space  at  immeas- 
urable distances  apart,  intensely  heated,  as  we  know, 
are,  in  comparison  with  that  supernal  nebular  heat,  as 
glow  worms  to  the  sun.  Extravagance  of  statement 
here  is  impossible.  Yet  all  this  energy  is  still  extant, 
but  where  ?  We  may  well  believe  that  the  ether,  though 
just  as  extensive  now  as  it  was  when  permeated  witli 
nebular  matter,  is  still  replete  with  this  energy ;  not 
quiescent,  which  is  impossible,  but  in  perpetual  transit 
in  specialized  forms  from  sun  to  sun  and  from  world  to 
world. 

The  existing  suns  of  course  form  the  nearest  ap- 
proximation to  the  once  existing  heat  of  nebulous  mat- 
ter. The  surfaces  of  these  suns,  or  their  photospheric 
envelopes,  are  still  in  a  state  of  the  most  violent  mole- 
cular agitation.  These  molecular  motions,  caused  by 
heat  alone,  give  rise  to  equally  intense  but  unspecialized 
ethereal  vibrations,  a  mixture  of  all  kinds.  This  is  the 
general  and  all-comprehending,  original  form  of  energy, 
the  raw  material  from  which  all  specialized  forms  are 
drawn.  As  the  sun  is  wholly  pervaded  by  this  gen- 
eral form  of  energy,  it  can  communicate  no  other  to 
the  ether,  and  the  ether  can  convey  no  other  from 
the  sun,  though  all  forms  are  wrapped  up  in  this  one. 


WHAT    IS    THE    ETHER?  199 

Hence  even  at  the  distance  of  our  earth,  and  much 
further,  the  sun  seems  to  give  out  light  and  heat  only. 
"But  this  unspecialized  condition  of  solar  energy  does 
not  and  cannot  continue  forever.  The  vibrations  of 
light  and  heat,  once  freed  from  the  solar  bodies  from 
which  they  emanate,  are  committed  entirely  to  the  cus- 
tody and  control  of  the  universal  ether. 

It  is  beyond  question  that  to  a  large  extent  these 
vibrations  become  specialized  or  assume  the  several 
forms  of  mechanical  force,  chemical  action,  and  what 
we  call  electricity  and  magnetism  when  communicated 
to  ordinary  matter.  How  do  we  know  this?  We 
know  that,  by  day  and  by  night,  we  are  surrounded 
on  all  sides  by  the  universal  ether,  and  also  by  the 
suns  that  stud  the  firmament.  Yet  we  receive  heat 
in  appreciable  quantities  only  from  one  body,  our  local 
sun,  either  direct  or  by  reflection.  If  all  the  suns  that 
inhabit  space  have  been,  for  infinite  ages  past,  pouring 
forth  floods  of  light  and  heat  equal  to  those  emanating 
from  our  sun,  all  space  would  now  be  full  to  repletion 
with  these  emanations,  provided  they  are  all  conserved 
and  all  remain  unchanged.  But  all  agree  that  they  are 
all  conserved.  The  only  conclusion  possible,  therefore, 
is  that  they  do  not  remain  unchanged,  but  take  on 
special  forms.  The  ether  brings  to  us  no  more  pyro- 
phorous  rays  to-day  than  it  did  five  thousand  years  ago, 
or  perhaps  untold  ages  ago.  It  is  therefore  reduced  to  a 
demonstration  that  the  pyrophorous  rays  of  the  sun  die 
out  and  come  to  nothing,  and  the  doctrine  of  conserva- 
tion with  them ;  or  that  these  rays,  comprehending 
in  their  incipiency  all  forms  of  energy,  are  imperisha- 
ble, but  capable  of  being  decomposed,  so  to  speak,  into 


200 


GRAVITATION. 


the  elementary  forms  of  energy  of  which  they  are 
composed. 

Of  these  we  are  now  considering  only  one,  that 
of  gravitation.  That  this  force  exists  none  will  of 
course  deny.  That  it  accompanies  the  earth  in  her 
orbit  all  round  the  sun  and  impels  the  earth  toward  the 
sun  at  every  point  in  her  orbit  is  equally  undeniable. 
It  must  therefore  be  a  force  operating  in  every  con- 
ceivable direction,  but  always  with  a  diminished  in- 
tensity on  the  line  connecting  the  sun  and  earth,  owing 
to  their  mutual  interceptions  of  this  force  from  each 
other. 

Whence  can  this  mechanical  force  arise?  It  cer- 
tainly cannot  emanate  from  the  sun  in  the  form  of  a 
radiant  propulsive  force.  If  so,  it  would  only  repel  the 
earth.  The  emanations  from  the  sun  at  the  distance  of 
our  earth  are  as  yet  almost  wholly  in  the  unspecialized 
form  of  heat.  I  can  see  no  possible  answer  but  to 
admit  what  every  physicist  claims,  viz. :  that  heat, 
which  certainly  emanates  in  vast  quantities  from  all 
solar  bodies,  is  the  unspecialized  fountain  of  energy, 
which,  by  means  that  we  cannot  fully  explain,  is  capa- 
ble of  being  specialized  into  other  forms  of  energy,  of 
which  mechanical  force,  acting  as  gravitation,  is  one. 

But  this  is  not  the  end.  In  fact,  there  is  no  end. 
When  the  unspecialized  energy  emanating  from  the 
solar  bodies  as  heat  has  been  transformed  into  mechan- 
ical force  and  other  special  forms,  it  is  ready  to  become 
again  despecialized  or  resolved  into  heat  by  impact 
with  these  same  solar  bodies,  and  so  on  forever. 

We  may  suppose,  and  have  good  reason  for  sup- 
posing, that  this  universal  ether  is  so  compressed  as 
more  nearly  to  resemble  a  solid  than  a  gas,  absurd  as  it 


WHAT    IS    THE    ETHER?  201 

may  seem.  "Not  only  that,  but  it  is  the  most  impene- 
trable body  in  existence,  though  with  so  little  inertia 
and  cohesion  that  all  non-ethereal  bodies  pass  through  it 
without  perceptible  resistance.  This  intense  pressure 
of  the  particles  of  ether  upon  each  other  gives  rise  to  no 
perturbations  among  themselves,  because  the  pressure, 
no  matter  how  great,  is  perfectly  equalized  ;  and  hence, 
as  before  observed,  ether  can  originate  no  vibrations. 
The  only  places  where  its  pent-up  power  can  find  vent 
and  wreak  all  its  wrath  are  the  hapless  suns  and  worlds 
inhabiting  space. 

Few  are  aware  of  the  tremendous  energy  enclosed  in 
the  ether,  unless  they  have  made  a  special  study  of  the 
subject,  or  like  the  writer,  have  availed  themselves  of 
the  researches  of  others  who  have  done  so.  I  quote 
from  "  Physics  of  the  Ether,"  by  S.  Tolver  Preston, 
page  115 : 

"To  give  an  idea,  first,  of  the  enormous  intensity  of  the  store  of 
energy  attainable  by  means  of  that  extensive  state  of  subdivision  of 
matter  which  renders  a  high  normal  speed  practicable,  it  may  be 
computed  that  a  quantity  of  matter  representing  a  total  mass  of 
only  one  grain,  and  possessing  the  normal  velocity  of  the  ether  par- 
ticles [that  of  a  wave  of  light],  incloses  a  store  of  energy  represented 
by  upward  of  one  thousand  millions  of  foot-tons,  or  the  mass  of  one 
single  grain  contains  an  energy  not  less  than  that  possessed  by  a  mass 
of  forty  thousand  tons,  moving  at  the  speed  of  a  cannon  ball  [one 
thousand  two  hundred  feet  per  second] ;  or  otherwise,  a  quantity  of 
matter  representing  a  mass  of  one  grain  endued  with  the  velocity 
of  the  ether  particles,  encloses  an  amount  of  energy  which,  if  en- 
tirely utilized,  would  be  competent  to  project  a  weight  of  one  hun- 
dred tons  to  a  height  of  nearly  two  miles  [one  and  nine-tenths  miles]. 

"  This  remarkable  result  may  serve  to  illustrate  well  the  intense 
mechanical  effect  derivable  from  small  quantities  of  matter  possess- 
ing a  high  normal  velocity,  the  extremely  high  value  of  the  effect 
depending  on  the  fact  that  energy  rises  in  the  rapid  ratio  of  the 
square  of  the  speed." 


202  GRAVITATION. 

This  writer  might  have  added  that  these  facts  may 
equally  well  illustrate  the  immense  quantity  and  high 
intensity  of  the  light  and  heat  derivable  from  this  me- 
chanical motion  arrested  by  the  sun. 

After  this  quotation  it  will  not  be  necessary  for  me  to 
argue  further  the  sufficiency  of  the  ether  as  the  power 
behind  the  throne  of  Phoebus.  But  whence  comes  this 
enormous  power  of  the  ether?  It  is  from  these  same 
suns,  discharging  all  their  fiery  intensity  of  energy  into 
this  same  ether,  all  of  which  is  conserved  and  active,  so 
maintaining  one  of  Nature's  endless  cycles. 

This  almost  inconceivable  intensity  of  energy  is  not 
merely  a  possible  or  potential,  but  an  actual  and  sleep- 
lessly  active  energy.  While  this  energy  maintains  its 
mechanical  form,  we  have  no  organs  sufficiently  sensi- 
tive to  apprise  us  of  its  existence.  In  the  form  of  me- 
chanical vibrations  bombarding  the  sun's  circumambient 
photosphere  of  incandescent  carbon  clouds,  and  chang- 
ing to  heat,  it  "  warms  and  illumes  creation  from  afar." 
Quoting  again  from  the  same  wrork,  page  89,  the  writer 
under  the  heading,  "  The  Identity  of  Physical  Pro- 
cesses in  Their  Fundamental  Nature,"  says: 

"We  have  observed  that  all  physical  processes  are  identical  in 
one  fundamental  respect,  in  that  they  all  consist  in  an  interchange 
of  motion.  The  interchange  of  motion  may  therefore  be  said  to  con- 
stitute the  simple  groundwork  or  fundamental  principle  upon  which 
all  physical  phenomena  in  their  vast  variety  are  based,  and  in  this 
one  circumstance  the  necessary  correlation  of  all  branches  of  physi- 
cal science  lies  at  hand.  The  fundamental  principle  is  itself  simple, 
yet,  from  its  very  nature,  consistent  with  the  production  of  phe- 
nomena of  endless  variety.  The  interchange  of  motion  may  be  said 
to  form  the  whole  basis  of  the  great  principle  of  conservation,  for 
the  very  idea  of  the  interchange  or  transference  of  motion  itself 
precludes  all  idea  of  the  possibility  of  the  annihilation  of  motion;  or 
the  only  possible  method  of  getting  rid  of  the  motion  of  a  mass  of 
matter  is  by  transferring  that  motion  to  another  mass  or  masses." 


WHAT    IS   THE    ETHER?  203 

This  shows  how  impossible  is  "  potential  energy." 
If  motion  is  transferred  from  one  body  to  another,  the 
latter  cannot  possibly  remain  motionless.  "All  energy 
is  kinetic."  This  quotation  also  clinches  the  doctrine 
that  the  sun  can  only  receive  his  heat  by  interchange 
with  the  ether,  as  this  is  the  only  body  with  which 
he  is  in  contact,  and  through  which  the  exchange  can 
be  made.  In  other  words,  the  ether  brings  to  the  sun 
the  heat  or  the  energy  from  which  his  heat  is  generated, 
and  by  return  wave  transports  the  same  to  every  point 
in  the  heavens. 

We  might  easily  suppose  the  ether  to  be  endowed 
with  sufficient  energy,  when  tapped,  so  to  speak,  to  fur- 
nish all  the  heat  required  by  the  sun.  But  then  the 
question  immediately  arises :  Why  does  not  the  earth, 
composed  of  the  same  materials,  exposed  to  the  same 
vibrations,  absorb  heat  therefrom  in  the  same  propor- 
tion, and  become  as  intensely  heated  as  the  sun '(  This 
question  seems  at  first  blush  unanswerable;  but  all 
truth  is  harmonious  at  bottom,  or  rather  at  top,  and  we 
have  not  far  to  look  for  a  principle  that  will  enable  us 
to  solve  the  difficulty. 

It  is  well  known  that  in  vibrations,  as  elsewhere  (evo- 
lution to  the  contrary  notwithstanding),  like  produces 
like.  In  a  musical  instrument  each  string  will  respond 
to  the  note  to  which  it  is  attuned,  but  is  silent  to  all 
others.  The  molecules  composing  the  sun's  photosphere 
are,  without  doubt,  in  that  wild  tumult  of  vibration  ex- 
actly adapted  to  excite  the  equally  tumultuous  ethereal 
vibrations  peculiar  to  heat  alone.  May  it  not  be  possi- 
ble that  the  ethereal  vibrations  arrive  at  the  sun's  sur- 
face in  the  orderly  and  specialized  forms  that  they  have 
assumed  in  their  measureless  transmissions  through 


204  GRAVITATION. 

space,  but  on  impinging  on  the  sun,  are  seized  upon,  and 
shaken  into  the  chaotic  vibrations  we  call  heat  ?  It  is 
not  necessary  to  suppose,  for  a  moment,  that  the  energy 
arriving  by  means  of  specialized  ethereal  waves  is  either 
increased  or  diminished  on  its  arrival  at  the  sun,  but 
only  that  it  is  there  changed  from  specialized  to  the  un- 
specialized  or  general  form  of  heat.  If  this  be  the  case, 
then  the  mystery  as  to  why  the  ethereal  waves  do  not 
turn  to  heat  at  the  earth,  disappears. 

The  earth  is  cold  and,  although  an  equal  quantity  of 
ethereal  waves  per  unit  of  surface  impinges  upon  the 
earth  as  upon  the  sun,  they  may  at  the  earth  undergo 
no  change,  or  a  comparatively  small  amount  of  change. 
They  may  and  probably  do,  in  part,  sink  into  the  earth 
in  the  form  of  magnetism  or  diffused  electricity.  A 
part  is  turned  to  heat  by  arrested  motion;  a  part  is 
employed  in  deflecting  the  path  of  the  earth  in  its  orbit, 
synonymous  with  gravitation,  and  a  part  will  be  re- 
flected and  pass  to  other  worlds. 

In  other  wrords,  may  it  not  be  true  that  all  waves  of 
every  kind  reaching  the  sun  are,  by  reason  of  the  pecu- 
liar and  intense  state  of  vibration  there  existing,  ab- 
sorbed and  turned  to  heat,  to  be  immediately  re-radiated 
in  all  directions,  while  exactly  the  same  kind  of  ethereal 
waves  and  the  same  amount  per  unit  of  surface,  im- 
pinging on  the  earth,  are  not  despecialized  and  turned 
to  heat,  but  fulfil  other  functions  just  as  important  in 
the  economy  of  nature  ?  When  these  messengers  from 
heaven  have  performed  the  duties  assigned  them  on 
earth,  they  resume  their  journeys  through  ether,  time 
and  space,  to  perform  similar  duties  in  other  suns  and 
worlds. 

The  theory  here  advanced  might  be  called  "  solar  neat 


WHAT    IS    THE    ETHER?  205 

by  means  of  metamorphosed  ethereal  waves."  It  har- 
monizes perfectly  with  the  theory  of  gravitation  here 
advocated.  One  of  the  specialized  forms  of  heat  is 
certainly  mechanical  force.  This  force,  set  free  and  act- 
ing in  all  possible  directions  through  the  heavens,  ex- 
cept where  it  is  intercepted  by  one  heavenly  body  from 
another,  as  I  have  often  explained,  exactly  fills  the  bill, 
if  I  may  be  pardoned  a  colloquialism,  for  gravitation. 
If  this  explanation  of  gravitation  impresses  other  candid 
minds  as  it  does  mine,  I  believe  the  great  Newtonian 
problem  will  soon  be  solved,  and  exactly  in  accordance 
with  undeniable  principles  laid  down  by  the  Great 
Master.  But  this  is  not  the  only  way  in  which  it  is  pos- 
sible for  the  mechanical  waves  inundant  on  the  sun  to  be 
metamorphosed  into  heat.  I  have  elsewhere  indicated  a 
very  plausible  one  by  means  of  the  electrical  vibration 
of  carbon  particles  in  the  photosphere  of  the  sun.  All 
that  I  claim  is  that  in  some  mode  of  metamorphosis,  or 
arrested  motion,  for  they  are  identical,  the  inconceivable 
intensity  of  action  of  the  waves  of  ether,  shown  by  the 
quotations  from  S.  Tolver  Preston,  is  transmuted  into 
heat. 


CHAPTER  XVIII. 

ETHEREAL  VIBRATIONS. 

This  medium;  is  it  not  infinitely  more  rare  and  more  subtile 
than  air,  and  exceedingly  more  elastic  and  more  active?  Does  it 
not  easily  penetrate  all  bodies?  And  is  it  not  by  its  elastic  force 
diffused  through  all  the  heavens?  —  SIR  ISAAC  NEWTON.* 

O1ST  tliis  subject  there  is  a  large  amount  of  abstruse 
learning.  I  shall  not  attempt  to  rehearse  this 
learning  here,  much  less  to  improve  upon  it.  We  are 
at  liberty,  however,  to  select  a  few  elementary  princi- 
ples, adapted  to  our  purpose,  without  prejudice  to  the 
rest. 

One  of  these  is,  that  there  are  vibrations  of  a  num- 
ber of  different  kinds.  It  is  utterly  impossible  that 
exactly  the  same  kind  of  vibrations  in  the  same  medium 
or  matter,  should  exhibit  the  phenomena  of  light  and 
heat,  chemical  affinity,  electricity,  magnetism  and  gravi- 
tation. The  kind  of  vibration  depends  on  the  kind 
and  condition  of  the  matter  by  which  the  vibration  is 
started,  or  rather  continued. 

Another  fundamental  principle  is  that  these  different 
kinds  of  vibration  can  and  do  change  from  one  form  to 
another  without  loss  of  motion,  which  once  begun  is 
eternal,  unless  stopped  by  a  miracle. 

Another  foundation  fact  is  that  all  ethereal  vibra- 
tions proceed  from  non-ethereal  matter,  and  can  be 
arrested  only  by  the  same  kind  of  matter. 

*  "  Optics."    Question  18. 
206 


ETHEREAL    VIBRATIONS.  207 

Again,  it  is  conceded  that  all  space  is  full  of  waves 
of  mechanical  force  propagated  in  all  directions.  I 
need  not  repeat  the  quotations  already  made  from  our 
most  highly  esteemed  scientists  to  prove  this  fact. 
These  waves  impinging  on  the  side  of  the  earth  turred 
from  the  sun,  and  similar  waves  being  intercepted  by 
the  sun  from  the  other  side,  constitute  the  force  of 
gravitation,  so  far  as  the  earth  is  concerned. 

Still  another  fact  is  that  the  vibrations  which  pro- 
duce light  and  heat  have  a  motion  transverse  to  the 
line  of  propagation,  and  also  a  forward-and-back  mo- 
tion. Without  this  last  there  could  be  no  line  of  propa- 
gation and  no  wave  length  from  crest  to  crest.  This 
last  form  of  wrave  may  be  rudely  compared  to  a  Vir- 
ginia rail  fence,  thus : 


FIG.  9. 


In  passing  from  a  rarer  to  a  denser  medium,  or  vice 
versa,  at  any  angle  with  the  perpendicular  less  than  the 
critical  angle  of  no  refraction,  the  ray  will  be  bent 
toward  or  from  the  perpendicular,  depending  upon 
whether  it  is  entering  or  leaving  the  denser  medium ; 
this  in  consequence  of  one  edge  of  the  ray  being  retarded 
by  the  denser  medium. 

Again  it  is  self-evident  that  a  ray,  if  there  be  such, 
composed  wholly  of  forward-and-back  motions  with  no 
side  wings  or  flanges  to  be  caught  and  retarded  by 
media  of  varying  density,  will  travel  in  straight  lines 
uninfluenced  by  refraction.  But  gravitation  is  a  fact, 
and  consequently  there  must  be  such  vibrations.  It  is 


208  GRAVITATION. 

mathematically  certain  that  these  lines  of  force  must  be 
straight,  and  not  curved  lines. 

Still  again,  gross  or  non-ethereal  matter  alone  can 
arrest  ethereal  waves,  and  the  waves  of  mechanical 
force  and  probably  all  forms  of  ethereal  vibrations,  heat 
excepted,  turn  to  heat  on  being  arrested.  As  infinite 
multitudes  of  these  wraves,  undulations,  vibrations  or 
rays  (for  all  these  terms  can  be  used  synonymously) 
are  impinging  on  celestial  bodies  and  turning  to  heat, 
it  follows  of  necessity  that  on  the  broad  stage  of  the 
universal  ether,  these  heat  waves  are  in  equal  quantities 
turning  to  waves  of  mechanical  force.  One  is  the  com- 
plement of  the  other.  In  every  light  and  heat  vibra- 
tion there  are  alternate  shells  of  compression  and  rare- 
faction, propagated  from  every  point  of  the  exciting 
cause.  But  what  may  be  the  exact  behavior  of  the 
individual  molecules  in  forming  and  propagating  these 
shells,  we  do  not  know  and  I  shall  not  attempt  to  guess. 

It  is  often  said,  and  truly,  that  the  molecules  com- 
posing the  undulations  of  light  and  heat  do  not  travel 
bodily  from  the  sun  to  the  earth  or  other  receiver. 
But  nevertheless,  the  whole  distance  from  the  sun  to 
the  earth  is  actually  travelled  many  million  times  every 
minute  on  every  line  of  radiation.  One  set  of  mole- 
cules does  not  travel  the  whole  distance.  Each  goes  a 
little  way  and  then  returns.  A  new  relay  at  every 
station,  of  which  there  are  said  to  be  fifty  thousand  to 
the  inch,  receives  the  motion  and  carries  it  the  fifty 
thousandth  part  of  an  inch  farther  and  returns  again  to 
its  starting  point. 

We  are  told  that  the  molecules  of  ether  or  some  of 
them  at  least,  in  the  undulations  of  light  and  heat, 
vibrate  transversely  to  the  line  of  propagation.  It  is 


ETHEREAL    VIBRATIONS.  209 

easy  to  see  how  this  not  only  may,  but  necessarily  must 
be  so.  In  fact  the  vibrations  producing  light  and  heat 
are  a  mixture  of  all  kinds.  It  is  therefore  equally  true 
that  some  of  these  molecules  must  vibrate  in  a  f  orward- 
and-back  line  of  motion,  parallel  with  the  normal. 

If  the  molecules  moved  only  in  planes  at  right 
angles  with  the  normal  or  line  of  propagation,  whether 
by  a  radial  or  a  rotary  motion,  no  forward  motion 
would  be  produced.* 

If  the  mixed  vibrations  represent  heat,  and  the 
forward-and-back  ones,  when  individualized,  represent 
mechanical  force,  it  is  easy  to  see  why  it  is  that,  in  the 
immeasurable  journeys  of  these  rays  through  space, 
heat  waves  resolve  themselves  into  waves  of  mechanical 
force,  that  is,  into  independent  forward-and-back  vibra- 
tions in  new  directions  by  their  ever  widening  expan- 
sion. The  forward-and-back  vibrations  are  incapable  of 
refraction,  and  move  only  in  right  lines.  These  last, 
as  already  explained,  are  by  the  sun  and  earth  mutu- 
ally intercepted  from  each  other  and  constitute  the 
force  of  gravitation.  The  portions  utilized  for  this  pur- 
pose, however,  being,  in  comparison  with  the  whole, 
infinitesimal,  the  unused  portions  pass  on  unspent  until 
they  impinge  on  some  of  the  suns  of  space,  as  every 
one  must  do,  sooner  or  later,  and  there  they  must  of 
necessity  turn  to  heat  by  arrested  motion,  and  so  help 
to  feed  the  solar  fires  of  the  universe,  thus  keeping  up 
an  eternal  round ;  heat  changing  not  only  to  mechani- 
cal force,  but  to  every  kind  of  energy  that  moves  the 
machinery  of  nature  and  sustains  life  in  all  its  forms, 
and  these  all  changing  back  again  to  heat,  and  so  on, 
forever. 

*See  Preston's  "Physics  of  the  Ether,"  pages  14,  15,  and  passim. 


210  GRAVITATION. 


A  DREAM  THAT  IS  NOT  ALL  A  DREAM. 

If  any  of  my  indulgent  readers  are  disposed  to  regard 
this  chapter  as  slightly  visionary,  I  will  endeavor  to 
make  good  in  a  very  few  words  the  latter  half  of  the 
quotation,  "  not  all  a  dream." 

1.  I  have  shown  from  Newton,  Maxwell,  and  many 
others,  what  is  almost  self-evident,  viz.:  that  action  at 
a  distance  is  impossible,  and  that  all  force,  gravitation 
included,  is  exerted  propulsively  through   a    material 
medium. 

2.  This  force  acts  upon  the  earth  at  every  point  in 
its  orbit,  and  consequently  must  be  moving  in  all  pos- 
sible directions,  ££  oupav&v  efc  oupavotx;,  from  the  heavens 
to  the  heavens. 

3.  A  force  acting  on  the  earth  or  sun  on  all  sides 
equally  would  not  change  their  lines  of  motion  in  the 
least. 

4.  It  must  then  be  weaker  on  the  side  of  the  earth 
turned  toward  the  sun  than  on  the  opposite  side.     This 
can  only  be  accounted  for  by  supposing  that  the  sun 
cuts  off  from  the  earth  a  portion  of  this  force,  and  vice 
versa. 

5.  This   force   operates  where   there  is  absolutely 
nothing  but  ether  for  a  medium,  and  must  therefore 
act  through  this  medium. 

6.  But  ether  acts  mechanically  only  by  means  of 
those  short  forward  and  backward  motions,  the  fifty 
thousandth  part  of  an  inch  in  length. 

7.  These  ethereal  vibrations  are  all  originated  prox- 
imately  by  the  grosser  forms  of  matter,  such  as  suns 
and  worlds  are  made  of,  and  as  these  vibrations  are 
moving  in  all  possible  directions,  how  can  we  avoid  the 


A  DKEAM  THAT  IS  NOT  ALL  A  DREAM.      211 

conclusion  that  all  suns  —  yea,  all  forms  of  non-ethereal 
matter  —  are  active  in  their  production  ? 

8.  Our  sun,  not  to  mention  the  innumerable  hosts 
of  other  suns,  is  in  most  urgent  need  of  vast  supplies  of 
light  and  heat  every  moment  to  replace  his  prodigal 
disbursements. 

9.  It  is  known  to  all  that  mechanical  motion,  arrest- 
ed, turns  to  heat.     But  all  space,  as  we  have  just  seen, 
is  occupied  by  ethereal  matter  in  vibratory  motion  in 
all   directions.      It   is   unavoidable   that   this    motion 
should  impinge  upon  the  sun,  and  turn  to  heat. 

10.  But  if  there  be  a  class  of  force-bearing  waves, 
constantly  turning  to  heat  by  arrested  motion  while 
they  break  upon  the  solar  shores,  then  there  is  just  as 
certainly  a  counter  process  going  forward  in  the  broad 
fields  of  ether,  where  heat  waves  turn  gradually  back 
to  waves  of  mechanical  force. 

11.  We  have  no  means  of  proving  by  actual  meas- 
urement that  the  amount  of  heat  given  out  by  our  sun 
is  exactly  equal  to  the  amount  returned  through  the 
same  ethereal  medium.      Neither   can  we   count  the 
drops  of  rain  that  descend  upon  the  earth,  nor  the 
globules  of  mist  that  ascend  from  it.     We  cannot  by 
actual  measurement  prove  that  the  amount  of  aqueous 
vapor  that  rises  through   our   atmosphere   is   exactly 
equal  to  the  amount  of  water  in  the  forms  of  rain,  hail, 
and  snow  that  descends  through  the  same  atmosphere. 
Yet  we  know  that  the  amounts  are  the  same  to  a  drop 
—  yea,  to  a  molecule  —  because  nothing  is  lost,  and 
nothing   can   escape.      It   matters   not  whether  these 
vapors  are  borne  to  the  north  pole  or  to  the  south. 
The  amount  that  comes  down  is  equal  to  the  amount 
sent  up.     It  is  just  as  undeniably  true  that  not  a  sun- 


212  GRAVITATION. 

beam  is  lost.  No  matter  how  wide  the  circuits  through 
which  they  pass,  nor  how  many  disguises  they  may 
assume,  the  incoming  vibrations  are  on  the  grand 
average  equal  to  the  outgoing.  The  amount  of  water 
from  ten  thousand  streams  poured  into  all  the  oceans 
of  earth  is  on  the  grand  average  equal  to  the  amount 
raised  from  these  oceans  by  evaporation.  The  ocean  of 
ether  is  incomparably  more  extensive  than  those  of 
earth,  but  the  waves  of  light  and  heat  are  no  more  lost 
by  radiation  into  this  ethereal  ocean  than  are  the  waters 
flowing  into  the  oceans  of  earth.  Conservation  in  both 
cases  guarantees  their  indestructibility,  and  nature's 
system  of  equilibrium  guarantees  their  distribution 
according  to  nature's  plan. 


CHAPTER  XIX. 

CONCLUDING  REMARKS  ON  GRAVITATION. 

Glide  on  in  your  beauty,  ye  youthful  spheres! 

So  weave  the  dance  that  measures  the  years, 

Glide  on  in  the  glory  and  gladness  sent 

To  the  farthest  wall  of  the  firmament, 

The  boundless  visible  smile  of  Him, 

To  the  veil  of  whose  brow  your  lamps  are  dim. 

— BRYANT. 

TO  recapitulate  :  All  forms  of  energy  travelling  by 
the  highways  of  ether,  unless  gravitation  is  an 
exception,  are  propagated  by  means  of  vibrations  or 
undulations.  But  gravitation  is  not  an  exception,  as  it 
is  convertible  into  heat,  molar  motion,  electricity,  etc.; 
therefore  gravitation  must  also  be  propagated  or  act  by 
means  of  vibrations.  As  there  is  no  medium  between 
the  earth  and  the  sun  except  ether,  it  must  be  propa- 
agated  through  the  vibrations  of  ether.  All  vibrations 
are  forward  from  the  senders  toward  the  receivers,  and 
those  assailing  the  earth  in  her  orbit  must  come  from 
a  direction  opposite  from  the  sun.  But,  for  another  rea- 
son, the  vibrations  which  impel  the  earth  toward  the  sun 
cannot  originate  at  the  sun  and  travel  to  the  earth,  be- 
cause this  would  occupy  time,  and  gravitation  is  instan- 
taneous. If  the  energy  of  gravitation  proceeds  from 
the  sun  to  the  earth  in  straight  lines,  the  earth  would 
have  changed  her  position  before  the  force  of  gravita- 
tion could  arrive. 

213 


214  GRAVITATION. 

If  gravitation  were  shot  forth,  so  to  speak,  from  the 
sun,  aimed  at  the  earth,  it  would  always  miss  the  mark 
and  could  never  overtake  the  earth.  On  the  contrary,  the 
earth  moving  in  her  orbit  finds  gravitation  in  operation 
at  every  point  in  advance  of  her  arrival.  The  same  is 
true  of  all  the  planets.  Therefore  gravitation  must  be 
a  force  coming  from  the  direction  of  the  starry  concave 
and  directed  toward  the  sun.  But,  as  shown  before, 
gravitation  is  not  due  alone  to  ethereal  vibrations  com- 
ing from  the  direction  of  the  starry  dome,  but  nega- 
tively to  the  interception  of  what  would  otherwise  be 
neutralizing  rays  from  the  opposite  direction. 

Gravitation  is  instantaneous  because  it  is  a  force 
present  and  acting  on  the  earth  at  every  point  in  her 
orbit ;  and  though  the  force  is  acting  in  the  direction  of 
the  sun,  it  acts  at  the  beginning  of  its  journey  from  the 
earth  to  the  sun,  instead  of  the  end  of  a  journey  from 
the  sun  to  the  earth. 

If  there  is  any  weight  in  great  names,  even  the 
greatest,  Xewton,  then  all  force  is  "vis  impressa  and 
ms  a  tergo;  "  that  is,  all  force  is  exerted  by  impact  and 
propulsively.  This  being  so,  there  is  no  escape  from 
the  conclusion  that  the  earth  is  borne  inward  toward  the 
sun  by  a  working  force  from  the  direction  of  the  stars 
and  operating  at  right  angles,  or  very  nearly  at  right 
angles,  averaging  as  if  at  right  angles,  with  those  small 
diagonals  of  small  parallelograms  that  make  up  the 
orbit  of  the  earth. 

Of  course  the  sun,  though  the  main,  is  not  the  only 
body  that  intercepts  undulations  of  mechanical  force 
from  the  earth,  and  therefore  the  motion  of  the  earth 
and  of  all  celestial  bodies  is  subject  to  perturbations. 
The  path  of  every  body  in  space  is  determined  by 


CONCLUDING    REMARKS    ON    GRAVITATION.  215 

an  equilibrium  of  all  the  interceptions  to  which  the 
body  is  subject  as  correlated  with  its  unwasting  tangen- 
tial motion.  Neither  the  earth  nor  any  other  planet 
ever  makes  two  revolutions  in  the  same  path,  even 
relatively  to  the  sun. 

It  is  universally  held  that  the  force  of  gravity  ex- 
erted by  the  earth  on  the  sun  is  exactly  equal  to  that 
exerted  by  the  sun  upon  the  earth.  If  the  earth  and 
sun  were  both  freed  from  the  action  of  all  other  forces 
except  gravitation  between  themselves,  the  earth  would 
move  toward  the  sun  three  hundred  and  thirty  thou- 
sand miles  to  one  that  the  sun  would  move  toward  the 
earth;  the  earth's  mass  being  to  that  of  the  sun  in 
about  that  ratio,  and  their  momenta  being  equal. 


FIG.  10. 


As  three  hundred  and  thirty  thousand  is  an  incon- 
venient number  to  handle,  either  mentally  or  manually, 
we  will  take  three  molecules,  #,  5,  <?,  to  represent  the 
earth,  and  six,  from  d  to  *,  to  represent  the  sun,  in 
the  following  figure,  as  the  principle  is  the  same  what- 
ever the  number. 

If  gravitation  were  exerted  by  pulls,  it  is  evident 


216 


GRAVITATION. 


that  each  of  the  molecules  #,  &,  c  would  exert  twice  as 
many  pulls  as  each  of  the  molecules  d  to  i,  and  would 
also  be  pulled  on  twice  as  many  times,  the  lines  repre- 
senting the  pulls  in  both  directions.  But  there  is  not 
even  a  spider's  thread  connecting  the  earth  and  sun  for 
these  bodies  to  pull  upon. 

We  will  now  introduce  a  figure  illustrating  gravita- 
tion by  propulsion,  in  which  the  earth  is  represented  by 
one  ball,  E,  and  the  sun  by  four  marked  S,  as  the  num- 
ber is  immaterial,  thus : 


FIG.  11. 


It  is  easy  to  arrange  four  candles  behind  the  one 
ball  E  in  such  a  manner  as  to  throw  its  shadow  cen- 
trally on  each  of  the  four  balls  marked  $  and  four 
other  candles,  one  behind  each  of  the  balls  $  $  S,  S.  so 
as  to  throw  the  shadows  of  each  centrally  upon  the  one 
ball  E.  In  this  case  the  ball  E  would  intercept  just  as 
much  light  from  the  four  balls  marked  S  as  the  latter 
would  from  the  former.  Any  other  kind  of  energy 


CONCLUDING    REMARKS    ON    GRAVITATION.  217 

acting  radially  would  be  governed  by  the  same  laws  as 
light. 

In  imagination  we  can  readily  increase  the  number 
of  balls  representing  the  sun  to  three  hundred  and 
thirty  thousand  or  any  other  number,  and  it  is  still 
manifest  that  one  ball  representing  the  earth  can  cast  as 
many  shadows  on  the  three  hundred  and  thirty  thou- 
sand representing  the  sun  as  these  latter  can  cast  upon 
the  one  ball  representing  the  earth. 

The  propulsion  theory  has  three  other  points  in  its 
favor  already  fully  presented,  which  to  our  apprehen- 
sion seem  conclusive : 

1.  Gravitation  by  attraction  is  impossible  for  want 
of  a  medium  capable  of  sustaining  a  longitudinal  strain 
tending  to  separate  its  "  transverse  interfaces,"  like  a 
string  or  a  rope,  while  propulsion  acting  by  waves  has 
in  the  universal   ether  exactly  the  kind  of   medium 
required. 

2.  The  traction  theory  supposes  the  force  of  attrac- 
tion to  be  inherent  in  the  particles  of  the  earth  and 
sun  respectively,  notwithstanding  Newton's  explicit  de- 
nial of  the  claim.     But  the  exercise  of  energy  of  any 
kind   involves  exhaustion  in  the   particles   concerned 
and  the  necessity  for  reimbursement.     This  reimburse- 
ment on  the  traction  theory  is  wholly  unprovided  for. 
On  the  propulsive  theory,  these  waves  are  just  what 
are  needed,  and  the  supply  is  inexhaustible,  because,  as 
elsewhere  shown,  all  celestial  bodies  are  both  senders 
and  receivers  of  these  impulses  in  a  never  ending  series. 

3.  Traction  is  impossible  because  the  matter  of  both 
earth  and  sun,  like  all  matter,  is  absolutely  inert  and 
unable  to  exert  any  force  whatever  suo  m,otu. 

But,  while  this  property  of  matter  absolutely  dis- 


218  GRAVITATION. 

qualifies  it  for  exerting  an  inherent  force  of  gravity,  it 
most  admirably  fits  it  to  play  its  part  in  gravitation  by 
propulsion.  The  inertia  of  matter  exactly  adapts  it 
for  arresting  and  transmitting  propulsive  vibrations, 
but  peremptorily  forbids  it  to  originate  motion  of  any 
kind.  Transmission  and  arrest  of  motion  are  the  only 
functions  required  of  matter  on  the  propulsive  plan, 
and,  I  may  add,  the  only  functions  for  which  it  is 
capacitated.  Originating  motion  is  an  act  of  creation. 
Molecules  and  masses  act  precisely  as  they  are  acted 
on ;  they  are  governed  by  the  iron  instead  of  the  golden 
rule.  They  do  unto  others  as  others  have  done  unto 
them.  Whence  then  comes  energy  ?  Not  from  atoms, 
but  from  the  Creator,  "  in  the  beginning." 


PART  III- SUN  SPOTS. 


CHAPTER  I. 

GENERAL  DESCRIPTION  AND  HISTORY. 

The  very  source  and  font  of  day 

Is  dashed  with  wandering  isles  of  night. 

— BELGRAVIA. 

FOR  nearly  three  hundred  years  the  scientific  world 
has  been  familiar  with  spots  on  the  sun,  discovered 
almost  simultaneously  by  Galileo,  Fabricius,  and  Schei- 
ner.  An  amusing  incident  is  related  of  the  latter,  who 
was  a  Jesuit  brother.  On  informing  his  superior  of 
his  discovery,  and  asking  to  be  allowed  to  publish  the 
same,  the  superior  replied  :  "  Go,  my  son ;  tranquillize 
yourself,  and  rest  assured  that  what  you  take  for  spots 
in  the  sun  are  the  faults  of  your  glasses  or  of  your 
eyes.  I  have  read  Aristotle's  writings  from  end  to  end 
many  times,  and  I  can  assure  you  that  I  have  nowhere 
found  in  them  anything  similar  to  what  you  mention." 
To  be  more  specific :  The  honored  name  of  Galileo 
is  credited  with  the  first  discovery  by  telescope  of  sun 
spots,  in  October,  1610.  Fabricius  followed  closely 
after,  in  December  of  the  same  year,  and  only  a  few 
months  later,  in  March,  1611,  Scheiner  made  the  same 
discovery.  All  were  original  discoveries,  as  each  worked 
in  entire  ignorance  of  the  labors  of  the  others.  As 
Fabricius  was  the  first  to  publish  his  discovery,  in  June, 

219 


220  SUN   SPOTS. 

1611,  the  discovery  is  credited  to  him,  though  the 
others  are  entitled  to  equal  honors. 

As  large  sun  spots  are  visible  to  the  naked  eye,  many 
were  no  doubt  seen  before  the  invention  of  the  tele- 
scope. The  records  of  that  curious  people,  the  Chinese, 
curious  in  two  senses,  afford  evidence  of  such  observa- 
tions. Dark  spots  had  also  been  observed  by  Kepler 
and  other  European  scholars  before  the  invention  of 
the  telescope ;  but  as  they  could  not  be  examined  in 
detail,  they  attracted  but  little  attention. 

These  spots  are  often  of  enormous  extent,  covering 
sometimes  millions  and  even  billions  of  square  miles. 
They  generally  open  as  small  points,  enlarge  rapidly 
till  they  attain  their  maximum,  and  after  a  period  of 
comparative  stability,  varying  from  a  few  days  to  sev- 
eral months,  fill  up  and  disappear. 

They  are  mostly  confined  to  that  part  of  the  sun's 
surface  corresponding  to  our  torrid  zone,  or  rather  to 
two  zones,  one  on  each  side  of  the  equator,  bounded  by 
parallels  about  thirty  degrees  north  and  south  of  the 
equator.  These  zones  of  maximum  sun  spots  shade 
out  each  way,  so  that  very  few  are  found  within  ten 
degrees  of  the  equator,  or  beyond  thirty  degrees  north 
and  south  of  the  same. 

These  spots  are  dark  at  the  bottom  and  partially 
lighted  on  the  penumbral  edges,  which  extend  to  the 
depths  of  thousands  of  miles. 

They  increase  and  diminish  in  numbers  at  nearly 
regular  periods  of  about  eleven  years.  The  upland  or 
plain  in  which  these  crater-like  openings  appear  is  of 
the  substance  denominated  the  sun's  photosphere ;  that 
is,  the  incandescent  surface  which  sends  forth  the  light 
and  heat  of  the  sun.  This,  as  I  venture  to  conjecture, 


GENERAL    DESCRIPTION    AND    HISTORY.  221 

is  composed  of  the  sublimated  vapors  of  carbon  float- 
ing in  an  atmosphere  of  metallic  gases.  Immediately 
below  the  surface  of  the  photosphere  is  the  stratum  of 
penumbral  clouds,  no  doubt  composed  of  the  same  ma- 
terials, but  at  a  lower  temperature.  Still  lower  is  the 
nucleus  or  body  of  the  sun,  sometimes  called  the 
umbra.  The  nucleus  is  generally  believed  to  be  liquid 
in  form,  but  by  some  to  be  composed  of  viscid  gases. 
The  spectroscope  seems  to  pronounce  in  favor  of  a 
liquid,  composed  of  the  most  refractory  elementary 
substances,  reduced  to  that  form  by  intense  heat. 
These  spots  often  pass  entirely  across  the  sun's  disc 
by  virtue  of  his  revolution,  and  have  sometimes  been 
mistaken  for  the  transits  of  inferior  planets.  The  sur- 
face of  the  nucleus  is  overlaid  by  transparent  absorbing 
gases,  by  the  action  of  which  the  Frauenhofer  lines 
of  the  spectrum  are  produced. 

The  appearance  of  these  spots  in  perspective  at  the 
edges  of  the  sun's  disc  clearly  shows  that  they  are  im- 
mense chasms  in  the  strata  of  the  photospheric  and 
penumbral  clouds,  laying  bare  for  the  time  the  inner, 
darker  and  cooler  nucleus  of  the  sun. 

They  are  exceedingly  variable  in  size  and  duration. 
One  has  been  seen  almost  two  hundred  thousand  miles 
in  diameter,  and  covering  an  area  of  twenty-five  billions 
of  square  miles.  Their  duration  also  varies  from  a  few 
hours  to  whole  days,  weeks,  and  months.  They  form  a 
puzzle  to  philosophers.  While  the  facts  are  obscure,  not 
for  the  want,  but  rather  the  excess,  of  light,  and  also  "the 
immense  distance  of  the  sun,  these  philosophers  have 
not  hesitated  to  draw  largely  upon  their  imaginations 
for  hypothetical  explanations.  There  is  no  harm  in 
this,  so  long  as  they  are  given  merely  as  hypotheses, 


222  SUN  SPOTS. 

and  kept  strictly  within  the  limits  of  known  facts.  A 
hypothesis,  to  be  of  any  value,  must  conform  strictly  to 
the  known  telescopic  and  spectroscopic  conditions  under 
which  these  spots  have  been  observed. 

It  is  entirely  unnecessary,  even  if  I  possessed  the 
time  and  qualifications  for  the  task,  to  examine  critically 
all  the  theories  advanced  in  explanation  of  these  phe- 
nomena. A  number  of  them  are  peremptorily  excluded 
by  telescopic  and  spectroscopic  observations.  Of  those 
remaining,  no  one  is  satisfactory  to  all  students  of  solar 
physics.  Anticipating  possibly  a  similar  fate  for  my 
own  theory,  I  proceed  to  unfold  it  for  what  it  is  worth. 


FIG.  12.— SPOT  OF  JULY  16,  1866. 

We  here  call  attention  to  a  very  symmetrical  illus- 
tration of  a  sun  spot,  from  "  The  Sun,"  by  Prof.  Young. 
We  quote  from  page  115,  on  which  this  figure  occurs, 
as  follows : 

"A  well  formed  solar  spot  consists,  generally  speaking,  of  two 
portions  —  a  very  dark,  irregular,  central  portion,  called  the  umbra, 


GENERAL    DESCRIPTION    AND    HISTORY.  223 

surrounded  by  a  shade  or  fringe  called  the  penumbra,  less  dark,  and 
for  the  most  part  made  up  of  filaments  directed  radially  inward. 
The  appearance  of  things,  under  ordinary  circumstances  of  seeing, 
is  as  if  the  umbra  were  a  hole,  and  the  penumbral  filaments  overhung 
and  partly  shaded  it  from  our  view,  like  bushes  at  the  mouth  of  a 
cavern.  I  say  as  if,  and  very  possibly  this  is  the  actual  case,  the 
central  portion  being  a  real  cavity  filled  with  less  luminous  matter, 
and  depressed  below  the  general  level  of  the  photosphere,  while  the 
penumbra  overhangs  the  edge." 

To  my  eye  the  penumbra  resembles  more  nearly  the 
shelving  banks  of  a  deep  excavation.  This  figure  also 
represents  beautifully  the  bright  points  called  "gran- 
ules," and  the  dark  reticulation  called  "  pores "  in  the 
general  surface  of  the  photosphere.  It  also  exhibits  to 
advantage  the  bright  fringe,  often  club-shaped,  at  the 
inner  edge  of  the  penumbra  hereafter  mentioned. 


CHAPTER  II. 

A  NEW  THEORY  OF  SUN  SPOTS  — THE  PHOTOSPHERE 
THE  HOTTEST  PART  OF  THE  SUN. 

And  now  the  sun  — 
Insufferably  brilliant,  and  his  blaze 
Tinges  with  flowing  gold  the  icy  head 
Of  peaks  which  rise  above  the  clouds,  and  gaze 
On  budding  landscape,  hills,  woods,  meadows,  lakes, 
Rivers,  and  winding  rivulets,  where  plays 
The  wave  in  lines  of  silver.  — PERCIVAL. 

WHEN  we  find  a  rule  to  which  there  is  no  excep- 
tion, it  rises  to  the  dignity  of  a  law ;  and  one 
law  thoroughly  understood  and  applied  will  often  throw 
a  flood  of  light  on  many  problems.  The  law  to  which 
I  wish  to  direct  attention  is,  that  the  more  highly  an 
elementary  body  is  heated,  the  more  brilliantly  white  it 
becomes.  Applied  to  the  sun,  we  find  the  faculae,  which 
are  the  crests  of  the  photosphere,  or  the  sun's  Hima- 
layan mountains  of  light,  are  the  most  dazzlingly  white. 
The  general  surface  of  the  photosphere  is  of  a  milder 
intensity,  and  the  brightness  continues  to  decrease 
through  the  penumbral  strata  to  the  nucleus,  which 
appears  to  be  entirely  black,  of  course  by  contrast. 
The  conclusion  seems  inevitable,  that  the  outer  envelope 
of  the  sun,  next  to  its  purely  gaseous  atmosphere,  is  by 
far  the  hottest  portion.  I  regard  the  photosphere,  with 
its  umbral  and  penumbral  strata  lying  in  immediate 
contact  with  the  nucleus,  as  a  part  of  the  sun  rather 

224 


A    NEW    THEORY    OF    SUN    SPOTS.  225 

than  of  his  atmosphere,  though  of  a  vaporous  or  cloud- 
like  texture. 

It  has  been  demonstrated  by  actual  experiments  that 
the  photosphere  is  much  hotter  than  either  the  pen- 
umbra or  nucleus.  The  spots  themselves,  as  Henry, 
Secchi,  Langley,  and  others  have  shown,  certainly 
radiate  to  us  less  heat  than  the  general  surface  of  the 
sun.  According  to  the  elaborate  determinations  of 
Langley,  the  umbra  of  a  spot  emits  about  fifty-four  per 
cent,  and  the  penumbra  about  eighty  per  cent  as  much 
heat  as  a  corresponding  area  of  the  photosphere.* 
This  shows  that  the  heat  of  the  photosphere  is  not  pro- 
duced by  conduction  or  convection  from  the  cooler 
regions  below,  and  consequently  must  come  from  with- 
out. This  photosphere  is  the  fountain  of  all  the  sun's 
radiations,  and  must  of  necessity  be  the  portion  cooled 
most  rapidly.  It  must,  therefore,  have  an  ample  source 
of  supply  independent  of  the  internal  heat  of  the  sun. 

There  seems  but  one  conclusion  possible,  and  that  is 
that  the  sun's  loss  by  radiation  is  supplied  from  without. 
Whence  can  it  come  ?  Only  from  other  suns  in  a  per- 
petual round.  The  universal  ether  is  proved  to  be  cap- 
able of  conveying  impulses  of  light  and  heat  not  only 
in  opposite,  but  in  all  possible  directions  at  the  same 
time.  The  sun's  light  and  heat  leave  that  luminary  by 
means  of  this  ether.  Can  we  doubt  that  they  return 
by  the  same  medium  ? 

That  the  planets  are  a  family  group  and  the  sun  their 
father  is  not  so  much  a  figure  of  rhetoric  as  a  literal  fact. 
There  are  many  things  looking  toward  a  common  origin 
and  of  course  a  common  nature  for  the  whole  solar  sys- 
tem, but  not  a  common  condition  at  the  present  time. 

*  "  The  Sun,"  by  Young,  page  159. 
15 


226  SUN  SPOTS. 

Now  the  earth  and  all  the  other  planets  have  this 
property  in  common ;  all  the  heat  lost  by  them  is  radi- 
ated from  their  outer  surfaces,  and  all  the  heat  received 
by  them  to  supply  the  loss  and  keep  up  the  equilibrium 
is  received  at  the  surface  from  the  sun  and  other  celes- 
tial bodies.  Analogy  would  teach  us  the  same  thing  is 
true  of  the  sun,  if  only  we  could  find  any  adequate 
source  from  which  this  heat  could  come.  However 
great  may  be  the  difficulty  in  finding  such  a  source  out- 
side of  the  sun,  the  difficulty  is  augmented  to  an  im- 
possibility, if  we  look  for  such  a  source  in  the  sun's  in- 
terior. I  have  discussed  this  subject  fully  in  another 
place  and  have  endeavored  to  show  that  there  is  no  lack 
of  abundant  supplies  of  light  and  heat  accessible  to  the 
sun  to  supply  all  his  loss  by  radiatioii. 

It  is  universally  conceded,  in  view  of  the  immense 
amount  of  heat  given  off,  that  the  sun,  if  unsupplied 
from  within  or  from  without,  would  cool  down  with  a 
rapidity  proportioned  to  the  loss.  It  would  only  be  a 
question  of  time  and,  according  to  the  best  authorities, 
a  brief  time  at  that,  when  the  sun  would  be  so  far  cooled 
down  as  to  render  the  earth  uninhabitable.  * 

We  will  endeavor  to  gain  an  idea  of  the  condition  of 
things  in  the  sun  by  transferring  the  scene  for  a  few 
minutes  to  the  earth.  Let  us  imagine  the  earth  to  be 
surrounded  on  all  sides  by  a  hollow  sphere  thickly 
studded  with  suns  as  hot  as  ours  and  capable  of  raising 
the  whole  body  of  the  earth  to  an  equal  temperature. 
What  would  take  place  ? 

In  the  first  place  all  organic  substances,  including 
mineral  coal  and  oils,  would  flash  into  one  vast  confla- 
gration, equal  in  grandeur  to  the  apocalyptic  vision. 

*  Newcomb's  "Popular  Astronomy,"  page  518. 


A    XEW    THEORY    OP    SUX    SPOTS.  227 

The  resulting  forms  would  be  mainly  carbon  dioxide,  or 
carbonic  acid  gas,  and  water  in  the  form  of  steam.  As 
the  heat  continued  to  increase,  this  steam,  together  with 
all  the  water  in  all  the  rivers,  lakes  and  oceans  also  con- 
verted into  steam,  would  be  decomposed;  and  the  im- 
mense volumes  of  hydrogen  and  oxygen,  thus  liberated, 
would  mount  skyward,  increasing  our  atmosphere  to  an 
enormous  extent.  Not  only  this,  but  all  the  oxidized 
earths  and  metals  would  be  decomposed  and  the  liber- 
ated oxygen,  heated  to  a  degree  far  beyond  the  point. of 
chemical  dissociation,  would  be  added  to  the  atmosphere, 
still  farther  increasing  its  enormous  volume.  As  if  there 
were  not  already  gases  enough  in  this  atmosphere,  the 
ever  increasing  heat  would  first  fuse  and  then  volatilize 
the  iron,  copper,  zinc,  and  probably  all  the  metals,  un- 
less we  except  platinum.  The  most  refractory  substances, 
such  as  silicon  and  platinum  would  probably  be  fused, 
and  lastly  would  come  the  cataclysmic  change  in  the  de- 
composition of  the  whole  volume  of  carbon  dioxide  into 
its  elements,  the  oxygen  joining  the  vast  volume  of  the 
gases,  and  the  carbon,  in  the  form  of  incandescent  vapor 
or  of  impalpable  atomic  dust,  descending  gently  in 
flocculent  clouds  of  fire  throughout  the  whole  expanded 
atmosphere.  When  these  fiery  vapors  had  settled  down 
to  loose  contact  with  the  molten  nucleus  still  remaining, 
they  would  form  a  photosphere  to  the  earth  entirely 
similar  to  that  of  the  sun. 

This  carbon  vapor,  or  impalpable  white-hot  atomic 
dust,  would  at  once  know  and  assume  its  proper  place, 
intermediate  between  the  pure  transparent  gases  above 
and  the  liquid  silicon  and  more  refractory  metals  com- 
posing the  core,  as  the  receiver  and  radiator  of  the  in- 
tense heat  of  these  surrounding  suns.  The  transf orma- 


228  SUN  SPOTS. 

tion  would  now  be  complete.     The  earth  would  he,  in 
all  respects,  a  little  sun. 

This  was  probably  once  the  condition  of  our  earth, 
but  it  has  now  cooled  down  so  as  to  become  the  fit 
abode  of  plants  and  animals,  and  even  of  frost  and 
snow.  And  yet  not  a  particle  of  its  heat  has  ever  been 
lost.  While  our  earth  has  been  cooling,  some  other 
world  or  worlds  have  been  warmed  into  fruitfulness  as 
the  theatres  for  animal  and  vegetable  life ;  or  if  suns 
were  needed  in  the  grand  economy,  the  heat  given  off  by 
our  earth  has  helped  to  kindle  other  suns,  or  still  more 
probably,  the  heat  given  out  by  our  earth  in  cooling 
has  been  replaced  by  tangential,  rotary  and  gravitative 
forces  with  other  forms  of  energy-  at  work  on  the  sur- 
face and  in  the  interior  of  our  globe.  Whatever  dispo- 
sition has  been  made  of  the  intense  heat  which  at  one 
time  liquefied,  if  it  did  not  volatilize,  the  substance  of 
our  earth,  two  things  may  be  affirmed  with  absolute 
certainty :  One  is  that  all  this  heat  is  somewhere  and 
in  some  form  conserved,  and  the  other  is  that  it  is  all  in 
active  operation,  which  is  merely  reaffirming  its  contin- 
ued existence,  for  energy  without  action  we  have  seen 
to  be  impossible. 


CHAPTER  III. 

THE  SUN'S   HEAT    DERIVED   FROM   THE   ETHER,   AND 
NOT  FROM  HIS  INTERIOR  — CAUSE  OF  SUN  SPOTS. 

A  golden  axle  did  the  work  uphold, 

Gold  was  the  beam,  the  wheels  were  orbed  with  gold, 

The  spokes  in  rows  of  silver  pleased  the  sight, 

The  seat  with  parti-colored  gems  was  bright ; 

Apollo  shined  amid  the  glare  of  light.  —  OVID. 

~TTT"IIAT  we  have  imagined  in  the  earth  is  exactly 
V  V  what  we  find  to  be  the  existing  state  of  things  in 
the  sun.  As  the  carbon  vapors  composing  the  photo- 
sphere radiate  all  the  heat  which  leaves  the  sun,  it  must 
be  cooled  the  most  rapidly  of  any  part;  and,  as  it  is 
always  the  hottest  part  of  the  sun,  it  certainly  cannot 
derive  its  heat  from  the  interior  and  cooler  portions. 
Consequently  it  must  come  from  without ;  from  the  sur- 
rounding ether. 

If  this  be  true,  then  the  sun  will  receive  his  heat  on 
all  sides,  and  the  poles  will  be  as  hot  at  least  as  at 
the  equator,  if  not  hotter.  This  we  find  to  be  the  case. 

It  maybe  asked — in  fact  has  been  asked,  "If  the 
photosphere  is  the  hottest  part  of  the  sun,  why  does  it  not 
by  conduction  raise  the  whole  interior  to  the  same  tem- 
perature ? "  I  reply :  The  photosphere  has  other  uses  for 
its  surplus  heat  in  warming  the  earth  and  other  worlds 
and  suns.  Being  in  contact  with  the  ether,  it  is  much 
easier  to  part  with  its  heat  by  radiation  than  by  the 
slower  process  of  conduction  through  gaseous  media  to 

229 


230  sux  SPOTS. 

the  sun's  interior.     At  all  events,  fact  is  fact,  whether 
it  suits  our  ideas  or  not. 

Affirmatively,  it  appears  to  me  highly  probable  that 
the  sun  spots  are  produced  by  a  relative  lowering  of  the 
temperature  of  the  photosphere  in  the  zones  where  the 
spots  occur.  As  it  is  held  by  all  the  best  authorities 
that  the  photosphere  is  composed  of  intensely  heated 
vapors  (I  think  carbon  vapors),  in  the  form  of  clouds, 
it  would  seem  most  natural  that  these  clouds  when 
slightly  cooled,  should  first  be  converted  into  a  line 
incandescent  mist,  then  to  fiery  rain,  hail  or  snow  (if  we 
may  use  old  words  with  new  meanings),  according  to 
the  nature  of  the  element  or  elements  composing  the 
sun's  photosphere.  In  this  way  large  regions  of  the 
photosphere,  if  sufficiently  cooled,  would  fall  to  the  sun 
in  the  form  of  solar  rain,  hail  or  snow,  or,  as  I  think,  in 
the  form  of  impalpable  carbon  dust,  leaving  the  inner, 
cooler  and  darker  surface  of  the  sun  uncovered,  just  as 
clouds  in  our  atmosphere,  when  condensed,  descend  in 
the  form  of  rain  and  snow,  and  leave  the  surface  of  the 
earth  previously  covered  with  clouds  open  to  the  inspec- 
tion of  the  inhabitants  of  other  worlds. 

The  extent  and  duration  of  these  spots  would  be  as 
variable  as  our  u  spells "  of  weather,  being  produced  by 
similar  causes,  viz.:  variations  of  temperature  in  the 
enveloping  atmospheres  and  clouds  of  the  earth  and 
sun  respectively.  If  our  earth,  like  Jupiter,  were 
always  covered  by  silver-lined  clouds,  with  the  lining 
on  the  outside,  and  if  only  occasional  rifts  occurred, 
exposing  the  earth's  surface,  the  inhabitants  of  other 
planets  would  call  them  earth*  spots,  and  the  fleecy 

*  Unless  the  inhabitants  of  other  worlds  have  other  names  for  our  planet. 


CAUSE    OF    SUN    SPOTS.  231 

clouds  would  form  a  mild  kind  of  mundane  photo- 
sphere. 

The  variations  in  the  temperature  of  our  atmosphere 
are  easily  accounted  for  by  the  extremely  diversified 
aspects  in  which  the  earth  presents  herself  to  the  sun, 
the  source  of  her  heat,  owing  to  the  variety  in  her  mo- 
tions and  the  inclination  of  her  axis.  But  in  the  case 
of  the  sun,  if  the  theory  that  he  receives  his  heat  equally 
from  all  parts  of  the  celestial  concave  is  correct,  then 
his  cloudy  envelope  at  least  ought  to  be  in  a  state 
of  comparative  rest.  Such  we  find  to  be  the  case. 
Only  two  narrow  belts,  one  on  each  side  of  the  sun's 
equator,  are  affected  by  sun  spots.  Of  course  so  unsta- 
ble a  thing  as  an  ocean  of  incandescent  hydrogen, 
mingled  writh  other  gases,  which  occupy  the  higher 
regions  of  the  sun's  atmosphere,  could  hardly  be  ex- 
pected to  be  entirely  quiescent  under  any  circumstances. 
On  the  contrary,  the  most  violent  convulsions  may  be 
expected  in  the  upper  regions  of  the  sun's  atmosphere. 
That  this  restful  condition  prevails  in  the  sun's  photo- 
sphere (not  in  his  chromosphere  and  corona),  seems 
probable  from  the  following  considerations : 

I  believe  every  writer  without  exception  considers 
the  photosphere  to  be  of  vaporous  or  cloud-like  texture. 
Consequently  it  would  yield  with  the  greatest  readiness 
to  any  disturbing  force  affecting  it  or  the  gaseous 
medium  in  which  it  floats.  But  the  sun  spots,  which  all 
admit  to  be  cavities  in  the  photosphere,  remain  not  only 
for  days  and  weeks,  but  often  for  months  without  being 
obliterated.  The  comparatively  restful  condition  of 
the  sun's  cloudy  envelope  forms  no  slight  corroboration 
of  the  truth  of  this  theory. 


SUN  SPOTS. 


CAUSE  OF  SUN  SPOTS. 

We  will  now  address  ourselves  to  an  attempt  to 
ascertain  the  cause  of  sun  spots. 

I  attribute  the  cooling  of  the  portions  of  the  sun's 
photosphere,  comprised  in  the  maculated  belts  (by 
which  large  fields  of  fiery  clouds  are  precipitated,  and 
the  sun's  surface  uncovered),  to  the  shadows  cast  upon 
the  sun  by  Jupiter  and  the  other  planets.  If  the  source 
of  the  sun's  heat  is  the  whole  celestial  concave,  then 
these  planetary  bodies  and  their  satellites,  mainly  lo- 
cated within  the  limits  of  the  zodiac,  are  the  only 
bodies  that  could  intercept  any  portion  of  the  waves 
inundant  on  the  sun. 

Of  course,  the  shadows  cast  by  the  heavenly  bodies 
are  very  different  from  those  we  are  familiar  with  on  the 
earth.  The  former  are  dynamic,  or  rather  anti-dynamic. 
They  are  simply  the  aggregate  of  the  shadows  of  the 
particles  composing  these  bodies.  I  hope  no  one  will 
decide  authoritatively  that  the  effect  of  these  shadows 
combined  must  of  necessity  be  infinitesimal,  while  he 
admits  that  a  force  which  we  call  gravitation  is  exerted 
between  the  sun  and  these  same  bodies,  which  is  by  no 
means  infinitesimal.  In  fact,  we  claim  that  the  energy 
intercepted  from  the  sun  by  these  bodies  is  identical 
with  gravitation.  It  consists,  as  we  conceive,  of  waves 
of  mechanical  force,  turning  to  heat  when  intercepted, 
coming  from  the  celestial  concave,  which  would,  if  un- 
intercepted,  make  the  equatorial  regions  of  the  sun 
equally  hot  with  his  poles,  but  being  intercepted,  ex- 
pends itself  in  bending  the  tangential  motion  of  the 
planets  into  the  curved  lines  of  their  orbits.  In  conse- 
quence of  the  diversion  of  this  intercepted  energy  to 


CAUSE    OF    SUN    SPOTS.  233 

the  purposes  of  gravitation,  the  sun  experiences  a  defi- 
ciency, greatest  near  his  equator,  where  the  intercepted 
rays  would  have  been  vertical,  and  shading  out  toward 
the  poles. 


CHAPTER  IY. 

ARGUMENT  FROM   THE  UNEQUAL  ROTATION  OF  THE 
SUN  SPOTS. 

• 

Thou  chief  star, 

Centre  of  many  stars  which  mak'st  our  earth 
Endurable  and  temperest  the  hues 
And  hearts  of  all  who  walk  within  thy  rays! 
Sire  of  the  seasons !     Monarch  of  the  climes, 
And  those  who  dwell  in  them  I  for  near  or  far, 
Our  inborn  spirits  have  a  tint  of  thee, 
Even  as  our  outward  aspects :  thou  dost  rise, 
And  shine,  and  set  in  glory.  —  BYROX. 

THE  sun  at  his  equator  revolves  on  liis  axis  in  about 
twenty-five  days.  At  twenty  degrees  north  and 
south  latitude  he  appears  to  revolve  in  twenty-five 
and  three-fourths  days;  at  thirty  degrees  in  twenty- 
six  and  a  half  days,  and  at  forty-five  degrees  in 
about  twenty-seven  and  a  half  days.  How  does  this 
accord  with  the  theory  here  advanced?  If  the  fiery 
clouds  composing  the  photosphere  are  relatively  cooler 
at  and  near  the  equator,  then  a  circulation  will  be 
set  up,  analogous  to  the  circulation  of  the  cloud-bearing 
winds  on  the  earth.  But  as  the  zones  are  reversed 
so  will  be  the  circulation.  The  cooler  portions  of 
the  photosphere  will  sink  down  and  flow  out  as  the 
under  currents  from  the  equatorial  regions  of  the  sun 
toward  his  poles.  These  out-flowing  currents  will  leave 
the  equatorial  regions  with  the  rotary  velocity  of  the 
nucleus,  but  will  be  continuously  retarded  by  friction 


UNEQUAL    ROTATION    OF    THE    SUN    SPOTS.  235 

till  they  reach  the  polar  regions,  by  which  time  they 
will  have  accommodated  themselves  to  the  slower  mo- 
tion of  the  nucleus  at  the  poles.  By  intermingling  and 
coming  to  the  surface,  these  currents  will  also  by  this 
time  have  acquired  the  higher  temperature  of  the  polar 
regions  where  110  shadows  are  cast  upon  the  sun.  They 
will  then  start  on  their  return  toward  the  equator  as 
the  upper  and  hotter  currents,  but  with  the  compara- 
tively slow  rotary  motion  of  the  polar  regions.  As 
these  currents  appoach  the  equator,  they  will  lag  be- 
hind the  motion  of  the  body  of  the  sun  most  at  first, 
but  will  become  gradually  accelerated  as  they  approach 
the  equator,  till,  on  arriving  in  the  equatorial  regions, 
they  will  have  regained  the  rotary  velocity  of  the  nu- 
cleus at  the  equator,  precisely  as  the  cloud-bearing 
winds  on  the  earth  are  alternately  accelerated  and 
retarded  in  their  rotary  motion  in  accommodating  them- 
selves in  turn,  now  to  the  swift  motion  of  the  equato- 
rial, and  then  to  the  slow  motion  of  the  polar  regions 
of  the  earth,  only  in  a  reversed  order.  This  circulation, 
on  the  supposition  of  a  relatively  cooler  zone  extending 
for  some  distance  north  and  south  of  the  equator,  is 
inevitable.  The  result  will  be  that  the  photosphere  in 
the  equatorial  regions  will  keep  pace  with  the  body  of 
the  sun.  But  north  and  south  of  the  equator  the  upper 
and  visible  portion  of  the  photosphere,  in  which  the 
spots  are  seen,  will  lag  behind  in  its  rotary  motion  in- 
creasingly from  the  equator  toward  the  poles. 

The  result  of  these  currents  must  inevitably  be  that 
the  photospheric  envelope  of  the  sun  will  keep  pace 
with  his  body  at  the  equator,  performing  a  revolution 
in  twenty-five  days,  while  those  portions  north  and 
south  of  the  equator,  with  their  included  spots,  will  be 


236  SUN  SPOTS. 

retarded,  and  will  take  longer  time  to  perform  a  revo- 
lution, just  in  proportion  to  their  solar  latitude.  This 
is  exactly  what  has  been  found  to  be  the  case  by  the 
patient  and  careful  observations  of  Carrington  from 
1853  to  1861.* 

I  can  see  no  probable,  nor  even  possible,  explanation 
of  the  slower  motion  of  the  sun  spots  north  and  south 
of  the  equator,  except  on  the  supposition  of  such  a  cir- 
culation as  I  have  described  ;  and  such  a  circulation  can 
only  be  produced  by  a  cooler  zone  at  and  near  the 
equator. 

We  call  these  grand  movements  of  the  photospheric 
and  penumbral  clouds  currents,  for  want  of  a  better 
term.  If  I  am  correct,  they  constitute  very  slow  mass 
movements  of  the  whole  vast  volume  of  the  sun's 
cloudy  envelope. 

I  have  elsewhere  shown  that  owing  to  the  fact  that 
the  sun  receives  his  heat  almost  equally  on  all  sides, 
there  are  no  great  inequalities  in  the  temperature  of 
different  parts  of  the  solar  surface,  and  consequently  no 
violent  currents,  as  upon  the  earth.  This  is  proved  by 
the  somewhat  permanent  character  of  the  spots.  These 
generally  remain  for  some  days,  and  often  for  weeks 
and  months,  with  but  slight  alterations  in  form.  .If 
violent  winds  were  sweeping  over  the  face  of  the  sun, 
the  spots,  being  of  a  cloudy  nature,  would  be  swept 
away  as  soon  as  formed.  The  flashes  and  streamers 
sometimes  observed  are  generally  considered  to  be 
auroral,  and  not  a  transference  of  actual  matter. 

Still,  there  are  undoubtedly  the  slow  currents  of  cir- 
culation I  have  described.  In  general,  they  are  divided 
into  upper  and  lower  currents,  as  in  our  atmosphere, 

*  See  "The  Sun,"  by  Young,  pages  133  and  134. 


UNEQUAL- ROTATION    OF    THE    SUN    SPOTS. 


237 


only  reversed,  as  the  cooler  and  hotter  zones  are  re- 
versed. But,  as  in  our  atmosphere,  so  in  the  sun,  these 
currents  sometimes  clash  and  become  mixed. 

In  the  sun's  northern  hemisphere,  the  currents,  both 
upper  and  lower,  relatively  to  the  solar  surface  as  seen 
by  us,  are  northwest  and  southeast.  It  will  be  remem- 

N 


bered  that  the  sun's  apparent  rotary  motion,  as  seen  hy 
us,  is  from  east  to  west.  These  upper  and  lower  cur- 
rents will  be  parallel  with  each  other,  but  in  opposite 
directions. 

If  the  arrows  represent  different  intermingling  cur- 
rents, it  is  plain  that,  should  a  sun  spot  be  located 


238  SUN  SPOTS. 

between  the  currents  a  b  and  c.  d,  their  edges  would 
revolve  from  left  to  right,  like  the  hands  of  a  watch ; 
the  same  between  e  f  and  g  h ;  but  between  the  cur- 
rents c  d  and  e  f,  and  also  between  g  h  and  i  j,  they 
would  revolve  from  right  to  left.  This  we  find  to  be 
the  case,  exhibiting  occasionally  the  appearance  of 
cyclones,  but  revolving  sometimes  in  one  direction,  and 
at  others  in  an  opposite  one.  Can  this  be  accounted 
for  on  any  other  hypothesis? 


FIG.  14.— CYCLONIC  SUN  SPOT,  BY  SECCHI. 

The  only  writer,  so  far  as  I  am  aware,  who  has 
attempted  to  account  for  the  cyclonic  character  of  the 
spots  is  the  ingenious  French  writer,  Faye.  But  his 
theory  would  require,  not  some  only,  but  all,  the  spots 
to  be  vortical,  and  would  further  require  all  spots  north 
of  the  sun's  equator  to  rotate  from  right  to  left,  and 
all  south  of  the  equator,  from  left  to  right ;  whereas,  it 
is  well  known  that  only  a  small  proportion  of  the  spots 
rotate  at  all ;  and  of  those  which  do,  some  rotate  in  one 


UNEQUAL    ROTATION    OF    THE    SUN    SPOTS.  239 

direction,  and  some  in  the  other,  in  the  same  hemi- 
sphere. Still,  the  theory  is  a  good  one,  and  all  that  is 
necessary  is  to  make  the  spots  conform  to  it. 


CHAPTER   Y. 

DISTRIBUTION  OF  SUN  SPOTS. 

Alcyone  shines  with  a  force  of  twelve  thousand  suns.  And  then 
we  have  suns  themselves  combined  into  systems  of  all  sizes  and 
shapes  —  systems  of  two,  of  three,  of  many,  of  millions  —  firma- 
ments which,  under  the  name  of  nebulae,  are  the  last  generalization 
and  most  stupendous  variety  of  modern  discovery;  sometimes  rolled 
up  into  spheres;  sometimes  gathered  into  circular  or  elliptic  rings: 
now  fan  shaped ;  now  like  an  hour  glass ;  now  broad  wheels  of  com- 
pacted suns,  large,  glittering,  and  sublime  enough  to  under-roll  the 
chariot  of  Omnipotence. — PATER  MUNDI. 

SUCH  is  a  glowing  description,  not  altogether  ima- 
ginative, of  the  suns  of  space  by  one  of  the  most 
eloquent  writers  of  modern  times.  .There  is  but  one  of 
this  innumerable  host  that  we  can  examine  with  any- 
thing like  exactness.  But  from  this  one  we  can  learn 
more  than  from  all  the  rest  combined. 

One  of  the  most  interesting  facts  in  regard  to  the 
"wandering  isles  of  night,"  called  sun  spots,  is  their 
peculiar  and  permanent  manner  of  distribution  upon 
the  solar  surface. 

We  have  seen  that  they  are  confined  almost  entirely 
within  two  parallels,  thirty  degrees  north  and  south  of 
the  sun's  equator,  diminishing  in  frequency  toward  the 
northern  and  southern  boundaries  of  these  belts,  and 
also  toward  the  equator. 

Figure  15  on  the  opposite  page  represents  the  sun 
with  the  plane  of  his  equator  inclined  to  that  of  the 


DISTRIBUTION    OF    SUN    SPOTS. 


241 


24:2  SUN  SPOTS. 

ecliptic,  or  plana  of  the  earth's  orbit,  at  an  angle  of 
seven  and  one-quarter  degrees,  together  with  the  planes 
of  the  four  other  planets  nearest  the  sun. 

The  planes  of  the  three  exterior  planets  are  omitted 
for  the  triple  reason :  1,  because  from  their  great  dis- 
tance they  can  have  but  very  little  influence  upon  sun 
spots;  2,  in  a  small  figure  the  planes  would  be  so 
crowded  as  nearly  to  obliterate  each  other ;  and,  3,  be- 
cause the  principle  can  be  as  well  illustrated  by  the  five 
nearer  planets  as  by  all.  It  will  be  seen  that  during 
one-half  of  the  years  respectively  of  each  of  the  planets, 
their  orbits  are  above,  and  during  the  other  half  below, 
the  sun's  equator.  As  the  planetary  years  differ  greatly 
in  length,  the  planets,  at  a  rough  average,  will  at  all 
times  be  distributed  in  nearly  equal  proportions  north 
and  south  of  the  sun's  equator,  as  well  as  in  their  direc- 
tions from  the  sun.  The  dotted  lines  will  represent 
those  parallels  on  the  sun  to  which  Mercury,  Jupiter, 
and  Venus  respectively  will  be  vertical  at  their  extreme 
northern  and  southern  limits.  They,  of  course,  repre- 
sent the  lines  on  which  these  planets  respectively  would 
be  most  influential  in  producing  sun  spots  at  these 
times.  But  the  planets  remain  at  their  extremes  of 
north  and  south  latitude  for  a  short  time  only,  and 
during  each  revolution  become  in  turn  twice  vertical  to 
the  equator  and  every  parallel  on  the  sun  between  these 
extremes. 

One  only  of  the  planets,  Mercury,  but  a  very  influ- 
ential one  on  account  of  his  proximity,  ever  extends 
his  north  and  south  latitude  sufficiently  to  make  his 
shadow  vertical  to  the  centres  of  the  maculated  belts, 
and,  of  course,  only  for  a  short  time  at  each  revolution. 
All  the  other  planets,  including  those  omitted  from  the 


DISTRIBUTION    OF    SUN    SPOTS.  243 

figure,  oscillate  from  one  side  of  the  sun's  equator  to 
the  other  within  much  narrower  limits. 

This  would  indicate  that  the  average  of  all  the 
shadows  cast  by  all  the  planets  must  be  densest  at  and 
near  the  equator,  fading  out  in  both  directions;  and 
the  sun  spots,  if  they  knew  how  to  behave  themselves, 
would  be  most  numerous  at  and  near  the  equator,  and 
would  shade  out  each  way  to  about  their  present  boun- 
daries. 

But  as  the  spots  will  not  conform  to  our  theories,  let 
us  see  if  our  theory  can  be  accommodated  to  the  spots. 

It  matters  not  at  what  point  we  start  in  to  accom- 
pany the  currents  in  the  photospheric  and  umbral 
clouds,  which,  as  we  believe,  circulate  from  the  equator 
to  the  poles  and  back  again.  We  will  therefore  join 
them  in  imagination  at  the  poles,  or  (confining  ourselves 
for  the  present  to  the  sun's  northern  hemisphere)  at  the 
north  pole.  Here  the  photosphere  is  exposed  to  the 
hottest  of  the  solar  skies,  and  becomes  heated  to  the 
highest  temperature  which  these  clouds  ever  attain. 
Thus  heated  they  start  toward  the  equator,  but  with 
the  very  slow  rotary  motion  of  the  circumpolar  regions 
of  the  sun.  The  result  is  that  they  wrill  lag  behind  the 
body  of  the  sun  during  their  whole  progress  from  the 
pole  to  the  equator,  and  when  the  currents  reach  the 
maculated  belts,  the  spots  will  also  lag  behind  just  in 
proportion  to  their  solar  latitude.  When  these  cur- 
rents reach  the  northern  boundary  of  the  maculated 
belt,  to  the  centre  of  which  Mercury  is  vertical  once  in 
every  eighty-eight  days,  they  begin  to  feel  the  cooling 
influence  of  the  planetary  shadows,  and  the  spots  com- 
mence to  appear,  though  sparsely  at  first. 

I  believe  there  is  no  dissent  among  scholars  as  to  the 


244  SUN  SPOTS. 

belief  that  even  what  are  called  the  pores  on  the  sun's 
surface  are  intensely  hot  and  brilliantly  white,  and  that 
they  only  appear  dark  by  contrast  with  the  still  hotter 
and  more  brilliant  granules  and  faculae  of  the  sun. 

It  is  well  known  that  almost  the  whole  surface  of 
the  sun  is  made  up  of  these  granules  and  pores  —  the 
pores  being  in  the  proportion  of  four  to  one  of  the 
granules  and  much  cooler  than  the  latter.  If  the  mat- 
ter of  both  is  the  same,  as  can  hardly  be  doubted,  then 
the  whole  surface  of  the  sun  is  nicely  balanced  on  the 
dividing  line  between  the  granular  and  porous  condi- 
tions. A  slight  increase  in  temperature  would  convert 
the  pores  into  granules  and  a  slight  lowering  would 
convert  the  granules  into  pores. 

To  continue  our  imaginary  journey :  When  these 
currents  in  their  southward  progress  have  reached  the 
parallel  of  twenty  degrees,  the  spots  become  most  nu- 
merous. As  they  approach  the  equator,  the  spots  again 
decrease,  till  at  about  ten  degrees  they  almost  entirely 
disappear. 

On  approaching  the  equator  the  currents,  being  now 
considerably  cooled,  dive  down  to  the  sun's  nucleus  and 
commence  the  return  voyage  as  the  undercurrent 
toward  the  pole.  This  journey  is  without  incident,  ex- 
cept that  the  upper  and  lower  currents  sometimes  clash 
and  intermingle  to  a  certain  degree,  as  in  the  cloud- 
bearing  atmospheric  currents  on  the  earth,  and  thus 
cause  occasional  cyclonic  action  in  the  spots.  These 
lower  currents  are  but  slightly  cooler  than  the  upper 
ones,  but  sufficiently  so  to  make  their  substance,  like 
the  pores,  appear  black  by  contrast. 

This  is  the  place  to  state  that,  according  to  the 
theory  here  advanced,  the  sun  spots  do  not  extend 


DISTRIBUTION    OF    SUN    SPOTS.  245 

downward  to  the  nucleus  of  the  sun,  but  only  to  this 
blackened  undercurrent  of  umbral  clouds.  We  are 
now  prepared  to  consider  the  question :  Since  the 
shadows  of  the  combined  planetary  system  are  densest 
on  and  near  the  equator,  why  should  not  the  spots  be 
most  numerous  in  this  part  of  the  sun  ? 

We  reply  that,  at  the  solar  equator,  and  for  some  dis- 
tance north  and  south  of  the  same,  this  celestial  Niagara 
of  glowing  carbon  clouds,  inconceivably  hot,  notwith- 
standing their  slight  comparative  cooling  by  the  plane- 
tary interceptions,  dives  down  to  an  unknown  depth 
and  then  turns  northward  and  southward  toward  the 
poles.  ISTow  suppose  an  ambitious  pore  on  the  upper 
surface  of  this  perpendicular  downward  current  should 
attempt  to  expand  itself  into  a  magnificent  sun  spot,  the 
downward  current  would  swallow  it  up  before  it  could 
be  formed.  Besides  this;  if  a  sun-spot  opening  could 
be  formed  in  the  upper  surface  of  this  downward  cur- 
rent, it  would  not  be  based,  as  in  the  other  cases,  upon 
the  blackened  surface  of  the  under  current,  which  is  not 
yet  fully  formed.  Thus  a  spot,  if  it  existed  on  or  near 
the  equator,  would  seldom  be  visible  for  want  of  a 
darker  background. 

It  seems  certain  that  the  edges  of  some  of  the  sun 
spots,  under  the  influence  of  some  mysterious  process, 
take  on  forms  of  grace  and  beauty  somewhat  resem- 
bling arborescent  frost  wrork  on  glass,  finely  depicted  in 
Prof.  S.  P.  Langley's  illustrations,  Figs.  18  and  21,  and 
also  in  Figs.  16  and  17. 

We  may  well  believe  that  between  the  parallels  of 
ten  degrees  and  thirty  degrees  the  restful  condition 
of  the  photosphere,  under  the  cooling  influence  of  the 
planetary  shadows,  is  highly  favorable  to  the  formation 


246 


SUN    SPOTS. 


first  of  enlarged  pores  developing  into  the  large  areas 
of  precipitation  known  to  us  as  sun  spots,  and  that  the 
tumult  and  rush  of  the  downpour  at  and  near  the 
equator  are  equally  unfavorable,  so  that  spots  here  will 
be  correspondingly  rare. 

Thus  we  see  that,  though  the  planets  do  not,  and,  in 
the  nature  of  things,  cannot,  cast  their  shadows  in  two 
zones  corresponding  to  the  maculated  belts,  still,  ow- 


FIG.  16.— SUN  SPOT  OP  JULY  31,  1869. 

ing  to  the  peculiar  nature  of  the  circulation  in  the  pho- 
tospheric  and  umbral  clouds,  in  connection  with  the 
planetary  shadows,  the  double-belted  distribution  is 
effected. 

It  may  be  replied :  What  proof  have  we  of  the  ex- 
istence of  this  circulation  ?  We  answer :  Two  undenia- 
ble facts.  One  is  the  lagging  motion  of  the  sun  spots, 
and  the  other,  their  occasional  cyclonic  action.  I  know 


DISTRIBUTION    OF    SUN    SPOTS.  247 

of  no  possible  way  of  accounting  for  either  of  these 
phenomena  except  by  such  a  circulation. 

Another  fact  is  equally  convincing.  If  it  be  con- 
ceded, or  has  been  proved,  that  the  sun  receives  his  sup- 
ply of  heat  from  the  stellar  concave  through  the  ether, 
then  it  is  as  certain  that  the  planets  must  intercept  a 
portion  of  the  energy  which  supplies  this  heat,  as  that  a 
screen  held  between  a  lighted  candle  and  a  wall  must  in- 
tercept a  portion  of  the  light  of  the  former  from  the  latter. 
It  is  just  as  certain  that,  if  motion,  or  energy  convertible 
into  heat,  be  intercepted  from  the  equatorial  region  of 
the  sun,  a  circulation  in  the  fleecy  clouds  of  the  photo- 
sphere and  umbra  must  be  produced. 

We  confess  that  it  seems  presumptuous  for  man  with 
his  limited  powers  to  intrude  "where  angels  might  fear 
to  tread."  We  stand  awe-struck  in  the  presence  of 
this  king  of  day,  and  hardly  dare  admit  to  ourselves 
that  we  are  able  to  penetrate  the  profound  secrets  of 
his  being.  But,  if  we  are  not  to  study  the  sun,  why  is 
he  allowed  to  exhibit  himself  to  us  in  all  his  glorious 
pomp,  and  why  were  we  endowed  with  the  powers  and 
the  desire  to  investigate  his  awful  mysteries? 


CHAPTER  YL 

PERIODICITY   OF  SUN  SPOTS. 
Nature  is  one  eternal  circle. — PERCIVAL. 

THE  sun  spots  increase  and  diminish  in  fairly,  but 
not  sharply,  defined  periods  of  about  11.111  years, 
according  to  Wolf. 

Now,  all  the  planets  move  in  orbits  more  or  less 
elliptical.  It  is  manifest  that  the  nearer  any  planet  is 
to  the  sun  —  that  is,  the  nearer  it  is  to  its  perihelion  — 
the  denser  will  be  the  shadow  cast  by  it  upon  the  sun. 
The  mass  of  each  planet,  divided  by  the  square  of  its 
distance,  will  express  its  relative  cooling  influence  upon 
the  sun.  Jupiter,  from  his  immense  mass  (being  three 
hundred  and  thirty-eight  times  that  of  the  earth,  and 
more  than  double  that  of  all  the  other  planets  com- 
bined), as  well  as  from  his  relative  distance  and  eccen- 
tricity of  orbit,  would  necessarily  dominate  in  the  mat- 
ter of  sun  spots.  Still,  he  will  sometimes  be  assisted, 
and  at  others  antagonized,  by  the  influence  of  the  other 
planets,  so  far  as  hastening  or  delaying  the  maximum 
periods  is  concerned. 

For  example,  every  forty-ninth  perihelion  of  Mer- 
cury, every  nineteenth  of  Venus,  every  twelfth  of  the 
Earth,  and  every  sixth  of  Mars,  will  very  nearly  syn- 
chronize with  those  of  Jupiter.  At  these  times  the 
maxima  will  probably  be  more  marked ;  at  others,  less 
so.  A.  Guillimin,  in  his  work,  "  The  Sun,"  page  209, 


PERIODICITY    OF    SUN    SPOTS.  249 

in  a  note,  speaking  of  Warren  De  La  Rue,  Balfour 
Stewart,  and  Loewy's  studies  in  relation  to  the  influ- 
ence of  Jupiter,  says : 

"They  appear  to  have  observed  that  when  one  of  these  planets 
passes  across  the  plane  of  the  sun's  equator,  it  drags,  as  it  were,  the 
spots  into  the  equatorial  region  of  the  disc;  they  spread  toward  the 
poles,  on  the  contrary,  when  the  planets  pass  away  from  the  equatorial 
plane. 'f 

This  negative  cause  of  sun  spots,  through  cooling  by 
planetary  shadows,  as  well  as  their  distribution,  is  won- 
derfully confirmed  by  a  writer  in  Belgravia,  No.  13, 
page  51,  without  knowing  or  intending  it,  thus : 

"But  it  was  reserved  for  the  patient,  day-by-day  watchers  and 
draughtsmen  of  our  time  to  discover  that,  as  Venus  rolls  in  her 
inclined  orbit  around  the  luminary,  the  spots  retreat  farther  from 
the  equator  as  the  planet  increases  her  solar  latitude;  in  other 
words,  that  there  is  a  tendency  in  the  spots  to  locate  themselves  per- 
pendicularly under  the  planet. 

"Another  curious  fact  evolved  from  the  daily  chronicling  is  that 
when  Mercury  passes  between  Venus  and  the  sun,  the  spots  come 
forth  in  the  fullest  splendor,  and  there  is  more  than  a  suspicion  that 
Mars,  in  conjunction  with  one  of  the  inferior  planets,  is  influential 
in  increasing  the  area  of  the  spottiness." 

This  writer  might  have  added  that  Jupiter,  and  all 
the  other  planets,  in  proportion  to  their  respective 
masses  and  proximity  to  the  sun,  aid  in  producing  this 
"  spottiness,"  and  that  their  solar  latitude  influences,  if 
not  absolutely  determines,  the  latitude  of  the  spots. 

After  reading  these  extracts,  how  is  it  possible  to 
doubt  that  the  spots  are  produced  by  the  shadows-  of 
these  and  the  other  planets  projected  on  the  sun  ? 

Adopting  Wolf's  periods  of  sun-spot  maxima  from 
1615  to  18TO,  a  period  of  two  hundred  and  fifty-five 
years,*  I  have  copied  the  following  table,  exhibiting 

*See  "The  Sun,"  by  Young,  page  148. 


250 


SUN    SPOTS. 


in  parallel  columns,  first,  the  dates  of  Jupiter's  peri- 
helia ;  second,  the  dates  of  the  corresponding  sun-spot 
maxima ;  third,  the  intervals  between  successive  sun- 
spot  maxima. 


JUPITER'S 
PERIHELIA. 

SUN  SPOT. 
MAXIMA. 

SUN  SPOT. 
INTERVAL. 

JUPITER'S 
PERIHELIA. 

SUN  SPOT. 
MAXIMA. 

SUN  SPOT. 
INTERVAL. 

1607.95 

1615.50 

1762.13 

1761.50 

11.20 

1619.81 

1626. 

iolso 

1773  99 

1769.70 

8.20 

1631.67 

1039.50 

13.50 

1785.85 

1778.40 

8.70 

1643.53 

1649. 

9.50 

1797.71 

1788.10 

9.70 

1655.39 

1660. 

11. 

1809.57 

1804.20 

16.10 

1667.25 

1675. 

15. 

1821.48 

1816.40 

12.20 

1679.11 

1685. 

10. 

1833.29 

1829.90 

13.50 

1690.97 

1693. 

8. 

1845.15 

1837.20 

7.30 

1702.83 

1705.50 

12.50 

1857.01 

1848.10 

10.90 

1714.69 

1718.20 

12.70 

1868.87 

1860.10 

12. 

1726.55 

1727.50 

9.30 

1880.73 

1870.60 

10.50 

1738.41 

1738.70 

11.20 

1881.70 

11.10 

1750.27 

1750.30 

11.60 

The  average  interval,  according  to  Wolf,  is  11.111 
years,  while  the  Jovian  period  is  11.86.  This  resem- 
blance between  the  two  periods  has  been  sufficient  to 
attract  the  attention  of  every  writer  on  the  subject.  Still 
there  is  sufficient  discrepancy,  coupled  with  ,the  irregular- 
ity in  the  intervals  of  the  maximum  periods,  to  puzzle 
the  philosophers  and  baffie  all  attempts  to  bring  them 
into  any  certain  relation  to  the  perihelion  periods  of 
Jupiter.  Much  less  has  anyone  attempted  to  point  out 
any  relation  of  cause  and  effect  between  the  two,  and 
still  less,  the  nature  of  that  cause. 

'Though  the  Jupiter  of  astronomy  is  not  chargeable 
with  the  fickleness  and  follies  of  the  Jupiter  of  mythol- 
ogy, there  certainly  seems  to  be  a  perverse  refusal  on 
the  part  of  the  former  to  square  his  conduct  with  the 
periods  of  sun-spot  maxima.  Still,  rather  than  throw 
aside  as  worthless  so  interesting,  though  imperfect,  a  cor- 


PERIODICITY    OF    SUN    SPOTS.  i}5 

respondence,  as  all  writers  on  the  subject,  so  far  as  I 
know,  have  done,  I  would  prefer  to  see  if  some  plan  of 
reconciliation  cannot  be  discovered. 

A  preliminary  observation,  in  which  all  will  agree 
with  the  writer,  is,  that  the  investigation  of  this  subject 
properly  belongs  to  astronomers  only.  But  anyone  may 
offer  suggestions  to  be  taken  only  for  what  they  are 
worth. 

My  first  observation  then  is  that  sun  spots  per- 
tain wholly  to  what  may  be  called  solar  weather,  or 
changes  in  solar  temperature.  The  weather  in  the  sun, 
though  far  less  complicated  than  that  of  the  earth,  par- 
takes, to  some  extent,  of  the  same  nature,  and  that  na- 
ture precludes  the  possibility  of  that  exactness  in  calcu- 
lation, which  the  sublime  science  of  astronomy  lias 
attained  in  regard  to  the  motions  of  the  heavenly  bodies. 

It  is  manifest  from  the  table  that  the  first  ten  sun- 
spot  maximum  periods,  as  compared  with  the  corre- 
sponding perihelia  of  Jupiter,  all  occurred  after  Jupiter 
had  circled  through  the  whole,  or  nearly  the  whole,  of 
the  perihelion  half  of  his  orbit  and  had  retired  to  the 
neighborhood  of  his  aphelion,  or  even  beyond,  leaving 
in  his  wake,  according  to  the  theory  here  advocated,  a 
cold  streak  encircling  the  sun  once  every  twenty-five 
days.  If  "  coming  events  cast  their  shadows  before,"  it 
is  no  less  true  that  departing  events  leave  their  shadows 
behind. 

Though,  in  these  cases,  Jupiter  has,  for  about  six 
years  on  an  average,  been  streaking  the  body  of  the  sun 
like  the  cylinder  of  the  phonograph,  with  lines  of 
lower  temperature,  he  certainly  has  enjoyed  the  aid  of 
the  perihelion  periods  of  other  planets  in  bringing  out 
the  sun-spot  maxima.  In  the  cases  where  the  maxima 


252  SUN  SPOTS. 

lag  behind  the  perihelia  of  Jupiter,  the  other  perihelia 
which  have  supplemented  his  work  have  followed  at  a 
respectful  distance  behind  those  of  the  former. 

From  1769  to  the  end  of  the  series  included  in  this 
table  nearly  the  same  process  is  repeated  as  from  16ir> 
to  1718.  The  sun-spot  maxima  occur  after  Jupiter  has 
swept  through  the  perihelion  half  of  his  orbit  in  most  of 
the  cases,  and  in  some  has  passed  on  to  and  even  beyond 
his  aphelion.  In  this  latter  series,  as  in  the  first,  it  is 
undoubtedly  true  that  the  sun-spot  maxima  have  in  part 
been  produced  by  the  perihelia  of  other  planets  follow- 
ing at  considerable  distances  behind  those  of  Jupiter. 

Between  1615  and  1881,  or  in  two  hundred  and  six- 
ty-six years,  twenty-four  sun-spot  maxima  have  occurred, 
as  generally  reckoned,  but  only  twenty-three  Jovian  pe- 
riods. In  other  words,  there  seems  to  be  a  slow,  though 
somewhat  irregular  precession  of  the  sun-spot  maxima 
over  the  Jovian  periods,  gaining  one  sun-spot  cycle  in 
about  two  hundred  and  sixty-six  years. 

Observers  are  not  fully  agreed  as  to  the  number  of 
maximum  periods  between  1615  and  1881.  If  we  were 
allowed  to  deduct  one,  it  would  make  the  number  of 
sun-spot  maxima  correspond  exactly  with  the  number  of 
Jovian  periods.  Will  the  reader  have  the  goodness  to 
recur  to  the  table  and  observe  that  between  1761.50  and 
1788.10  —  an  interval  of  26.60  years  —  three  successive 
maximum  periods  are  included,  averaging  only  8.86 
years  each.  Whereas,  the  general  average  is  11.11,  or, 
allowing  the  deduction,  11.86.  If  these  three  could  be 
reduced  to  two,  without  doing  violence  to  the  facts  of 
observation,  it  would  show  such  a  close  correspondence 
between  the  average  of  the  sun-spot  cycles  and  the  pe- 
riods of  Jupiter  as  would,  I  believe,  convince  every  can- 


PERIODICITY    OF    SUN    SPOTS.  253 

did  reader  that  the  latter  are  responsible  for  the  former. 
We  could  hardly  refrain  from  crying,  "  Eureka ! " 

In  -the  few  cases  between  1718  and  1769  where  the 
sun-spot  maxima  and  the  Jovian  perihelia  were  nearly 
contemporaneous,  the  perihelia  of  other  planets  which 
did  the  preliminary  work,  leaving  the  finishing  strokes 
only  to  Jupiter,  evidently  preceded  those  of  Jupiter. 

That  there  were  such  preceding  and  following  peri- 
helia of  other  planets  goes  without  saying.  Mercury 
is  in  perihelion  every  eighty-eight  days.  Venus  follows 
once  in  every  two  hundred  and  twenty-five  days,  while 
Earth  and  Mars  are  in  perihelion  every  three  hundred 
and  sixty-live  days  and  six  hundred  and  eighty-seven 
days  respectively.  As  to  their  exact  positions  while 
rendering  to  Jupiter  their  aid,  we  prefer  to  leave  them 
to  the  exact  calculations  of  the  practical  astronomer, 
rather  than  to  the  bungling  figures  of  an  inexpert. 

I  shall  not  be  surprised  to  learn  from  those  compe- 
tent to  make  the  calculations  that  every  variation 
between  the  Jovian  periods  and  the  sun-spot  cycles  can 
be  accounted  for  by  intervening  planetary  perihelia. 

The  general  law,  I  apprehend,  might  be  expressed 
thus :  Let  the  mass  of  each  of  the  planets,  including  its 
satellites  and  each  of  the  planetoids  be  divided  by  the 
square  of  its  distance  from  the  sun ;  then  the  sun  spots, 
in  number  and  magnitude,  will  vary  directly  as  the 
sum  of  these  quotients. 

This  expresses  the  order  only  of  the  changes.  The 
time  that  will  elapse  between  the  occurrence  of  the 
cause  and  the  exhibition  of  the  effect  will  always  be 
considerable,  just  as  our  coldest  weather  occurs  some 
time  after  the  winter  solstice,  and  our  hottest  after  the 
summer  solstice.  The  length  of  these  intervals  is  not 


254  SUN  SPOTS. 

only  unknown  beforehand,  but  is  subject  to  considera- 
ble variations  in  different  Jovian  years. 

This  law  might  be  more  loosely  and  popularly  ex- 
pressed thus :  The  nearer  the  whole  aggregate  mass  of 
planetary  matter  is  to  the  sun,  the  more  effective,  nega- 
tively, will  be  the  penumbral  shadows  or  negations  of 
energy,  or  the  greater  will  be  the  number  of  rays  of 
mechanical  motion  convertible  into  heat,  intercepted 
from  the  sun,  and  the  more  will  his  photosphere  between 
the  limits  of  the  zodiac  and  for  some  distance  beyond, 
be  cooled  and  condensed,  and  the  greater  will  be  the 
number  and  size  of  the  openings  through  the  photo- 
spheric  clouds  called  sun  spots.  But  the  intervals 
between  these  periods  of  greatest  average  proximity 
and  the  occurrence  of  the  sun-spot  maxima  are  variable 
within  certain  limits. 

But  with  these  small  concessions  to  Mercury,  Venus 
and  the  other  inferior  deities,  Jupiter,  as  might  be 
expected,  has  no  doubt  ruled  in  the  heavens  for  ages 
before  his  worship  was  celebrated  on  Mount  Olympus. 
He  dominates  in  the  matter  of  sun  spots,  but  he  is 
obliged  to  share  his  sovereignty  with  every  planet, 
every  satellite,  and  every  asteroid,  that  circles  round  the 
sun.  Every  body,  large  or  small,  situate  between  the 
celestial  concave  and  the  maculated  belts  of  the  sun, 
helps  to  cast  shadows,  or  negations,  upon  the  latter,  and 
by  so  doing  deprives  these  portions  of  the  sun  of  a  cer- 
tain amount  of  mechanical  motion  convertible  into 
heat,  which  all  other  portions  of  the  sun  receive  in  un- 
diminished  plenitude  and  intensity. 

These  shadows  of  intercepted  energy  cause  a  relative 
cooling  of  the  photosphere  of  the  spotted  belts  and  a 
condensation  of  the  photospheric  clouds  in  "  spots/'  thus 


PERIODICITY    OF    SUN    SPOTS.  255 

opening  rifts  through  which  we  catch  glimpses  of  the 
interior  of  the  sun. 

The  relation  between  sun  spots  and  terrestrial  mag- 
netism is  well  established  and  highly  interesting,  but  all 
that  is  known  on  the  subject  can  easily  be  found  in  the 
works  of  more  learned  writers.  It  is  highly  probable, 
though  not  yet  fully  demonstrated,  that  the  years  of  sun- 
spot  maxima  are  slightly  cooler  than  the  average.  If 
so,  though  I  have  not  investigated  the  subject,  it  may 
be  found  that  in  these  years  the  grasses  and  cereals, 
except  maize,  have  been  abundant,  wrhile  during  the 
minimum  periods,  the  reverse  has  been  the  case. 


CHAPTEK  VII. 

THE   PHOTOSPHERE  PROBABLY  COMPOSED  OF   INCAN- 
DESCENT CARBON  VAPOR. 

The  sun's  high  palace,  on  high  columns  raised, 
With  burnished  gold  and  flaming  jewels  blazed. 

— OVID. 

IT  is  the  almost  universally  received  opinion  that  the 
sun  and  planets  have  a  common  origin.  It  is  not 
simply  suspected,  but  fully  demonstrated,  that  a  major- 
ity of  the  best  known  elementary  substances  which 
compose  the  earth  exist  also  in  the  sun.  As  to  the 
mundane  elements  that  have  not  been  discovered  in  the 
sun,  we  may  well  believe  that  their  presence  has  not 
been  detected,  through  the  imperfections  of  our  means 
of  observation. 

As  the  sun  has  only  one-fourth  the  density  of  the 
earth,  these  materials  must  be  in  forms  much  more 
expanded  than  in  the  earth. 

This  need  not,  however,  be  gaseous,  so  far  as  the 
nucleus  or  inner  core  is  concerned.  It  is  much  more 
probable,  in  my  opinion,  though  I  cannot  stop  here  to 
give  the  reasons,  that  the  inner  portion  of  the  nucleus 
is  liquid,  or  possibly  composed  of  the  most  refractory 
solids,  held  in  this  form  by  enormous  pressure.  The 
outer  portions,  being  subjected  to  the  action  of  greater 
heat  and  less  pressure,  are  known  to  exist  in  the  gas- 
eous form. 

As  the  elements  of  the  earth  and  sun  are  mainly,  if 

?56 


INCANDESCENT    CARBON    VAPOR.  257 

not  entirely,  the  same,  it  is  highly  probable  that  they 
exist  in  the  two  bodies  in  similar  proportions.  As 
about  one-half  the  mass  of  the  earth  is  composed  of 
oxidized  silicon  or  silex,  we  may  presume  that  the 
great  mass  of  the  sun  consists  of  silicon  and  oxygen 
uncombined,  because  all  substances  in  the  sun  are  heated 
up  to  and  beyond  the  point  of  chemical  dissociation. 

This  elementary  substance  has  never  been  fused  by 
any  heat  that  can  be  produced  on  the  earth  or  concen- 
trated from  the  sun  ;  and  if  any  substance  could  remain 
unmelted  in  the  sun,  it  would  probably  be  silicon. 

We  find  the  earth  to  be  finished  off  with  an  irregu- 
lar veneering  of  carbon  on  or  near  its  surface.  This 
location  of  the  carbon  on  the  earth  is  not  accidental, 
but  results  from  the  operation  of  natural  laws. 

All  the  carbon  of  the  earth,  probably  not  excepting 
even  the  small  portion  existing  in  the  form  of  the  dia- 
mond, has  been  drawn  from  the  atmosphere  by  the 
decomposition  of  carbon  dioxide,  or  carbonic  acid  gas, 
by  the  agency  of  sunlight  acting  through  the  vegetable 
kingdom.*  Of  course,  this  carbon  must  be  deposited  on 
or  near  the  surface  of  the  earth.  For  other  reasons, 
we  may  expect  to  find  the  carbon  of  the  sun  at  his  sur- 
face as  the  dividing  stratum  between  his  nucleus  and  his 
atmosphere  proper.  Though  we  meet  with  pure  carbon 
on  the  earth  in  several  allotropic  forms,  we  find  it  in 
two  conditions  only  as  affected  by  heat,  viz. :  the  solid 
and  the  vaporous  or  volatilized ;  never  as  a  liquid  nor 
as  a  gas,  unless  volatilized  carbon  be  gaseous. 

One  thing  seems  certain,  that  is,  that  the  visible  sub- 
stance of  the  photosphere  is  apparently  opaque,  and 
appears  to  us  simply  as  the  radiator  of  intense  light 

*  Newton,  for  optical  reasons,  suspected  the  diamond  to  be  of  vegetable  origin. 
17 


258  SUN  SPOTS. 

and  beat.  Speaking  of  things  of  which  we  know  little, 
it  may  be  said  that  probably  all  bodies  must  exist  in  a 
gaseous  or  ultra  gaseous  form  before  separation  can  take 
place  into  the  ultimate  particles.  Also,  that  all  particles, 
even  those  of  the  most  transparent  gases,  are  solid 
bodies,  and  that,  in  a  highly  incandescent  condition, 
they  appear  opaque,  but  glitteringly  bright.  Carbon  in 
this  condition  might  appropriately  be  called  diamond 
dust,  if  we  can  conceive  of  dust  of  the  fineness  of  the 
ultimate  particles  of  matter. 

Still,  it  is  not  necessary  for  our  purpose  to  suppose 
that  carbon  exists  in  the  photosphere  in  the  form  of  gas. 
It  is  more  probable  that  it  exists  in  the  finely  divided 
form  which  we  see  in  flames  or  in  the  electric  arc. 

I  have  seen  in  the  cabinet  of  Prof.  H.  S.  Carhart,  in 
the  Northwestern  University,  and  I  presume  there  are 
many  such  cases,  an  Edison  lamp  in  which  one  arm  of 
the  carbonized  bamboo  was  ruptured  and  a  portion  of 
the  carbon  volatilized.  The  carbon  was  deposited  as  a 
fine  dust  all  over  the  inner  surface  of  the  bulb,  except 
on  a  fine,  straight,  perpendicular  line,  exactly  opposite 
the  remaining  arm  of  the  bamboo,  showing  conclu- 
sively that  the  volatilized  carbon  radiated  out  in  all 
directions  in  straight  lines,  like  light,  except  where  it 
was  intercepted  by  an  intervening  obstacle. 

This  tends  to  show  that  volatilized  carbon  in  a  vacu- 
um is  not  gaseous.  If  it  were,  it  would  have  filled  the 
glass  bulb  and  pressed  equally  on  every  part  until 
condensed  by  cooling.  The  same  would  have  been 
true  if  the  carbon  was  in  the  form  of  vapor,  as  com- 
monly understood.  Therefore  I  incline  to  the  opinion 
that  carbon,  when  not  an  ordinary  solid,  is  in  the  form 
of  impalpable  dust,  and  in  that  condition  forms  the 


INCANDESCENT    CARBON    VAPOR.  259 

photosphere  of  the  sun.  However,  as  the  photosphere 
more  nearly  resembles  the  clouds  of  our  sky  than  any 
other  form  of  matter  we  are  familiar  with,  I  shall  con- 
tinue to  speak  of  it  as  composed  of  vapor,  that  is,  car- 
bon vapor.  This  impalpable  dust  is  slightly  denser 
than  the  gases  in  which  it  floats,  and  dances  in  them 
as  freely  as  the  motes  in  our  atmosphere.  Being  slightly 
denser,  this  carbon  dust  will  seek  the  lower  levels  of  the 
sun's  atmosphere. 

Like  nearly  all  other  forms  of  matter,  the  cooler  por- 
tions will  be  the  densest  and  will  form  the  lowest  strata, 
or  rest  upon  the  nucleus  of  the  sun.  In  fact,  it  may 
cover  this  nucleus  for  thousands  of  miles  in  depth,  as 
loosely  deposited  masses  of  incandescent  impalpable 
powder.  If  the  sun  receives  and  parts  with  his  heat 
at  the  surface,  as  I  have  supposed,  the  outer  surface  of 
this  photosphere  will  always  be  the  hottest  and  brightest 
part  of  the  sun,  and  the  lower  we  descend  in  imagina- 
tion through  this  vast  enveloping  cloud,  the  less  highly 
heated  and  the  less  brilliant  it  will  be  found.  Although 
it  is  not  probable  that  the  lowrest  and  coolest  part  of 
these  clouds  falls  below  a  white  heat,  yet,  in  contrast 
with  the  intensely  heated  and  glittering  brightness  of 
the  surface,  the  lowest  stratum  of  the  photosphere  will 
appear  entirely  black.  Whether  or  not  this  carbon 
vapor  or  atomic  dust  assumes  the  liquid  form  on  cooling 
we  may  never  know  to  a  certainty.  But  even  if  it 
does  not,  it  doubtless  undergoes  changes  analogous  to 
the  condensation  and  falling  to  the  earth  of  aqueous 
vapors.  When,  therefore,  sun  spots  occur,  large  areas, 
sometimes  amounting  to  millions  and  billions  of  square 
miles,  of  this  photosphere  are  cooled,  condensed  and 
precipitated  on  the  nucleus  of  the  sun.  These  precipi- 


260 


SUN    SPOTS. 


tated  vapors  at  the  nucleus  will  now  be  exposed  to  the 
concentrated  rays  of  the  sunny  concave.  The  revola- 
tilization  of  the  precipitated  carbon  will  be  resumed 
and  the  cavity  will  ultimately  be  refilled  with  photo- 
spheric  carbon  clouds. 

The  atmosphere  in  which  these  carbon  vapors  float 
is  composed  largely  of  the  gases  of  iron  and  other 
metals.  As  in  our  atmosphere  there  is  a  certain 
stratum  in  which  the  clouds  float,  so  in  the  sun's  atmos- 
phere there  is  a  certain  stratum  whose  density  is  ex- 
actly adapted  to  the  clouds  forming  the  photosphere. 


PROOFS. 


As  it  has  never  yet  been  proved  that  carbon  exists  at 
all  in  the  sun,  much  less  that  his  entire  photosphere  is 
composed  of  this  element,  it  is  not  to  be  expected  that 
this  theory  will  meet  with  ready  acceptance  without 
some  considerations  tending  to  show  its  probability  at 
least.  I  present  the  following : 

1.  Carbon  exists  in  large  quantities  and  in  various 
forms  in  the  crust,  on  the  surface  and  in  the  atmos- 
phere of   the  earth,  and   in   many  of  the  meteorites 
falling  on  the  earth.     Analogy  would  lead  us  to  expect 
its  presence  in  some  form  in  the  sun. 

2.  Carbon  is  the  source  of  nearly  all  the  artificial 
light  and  heat  that  exists  on  the  face  of  the  earth.     It 
warms  and  lights  our  dwellings,  cooks  our  food,  reduces 
our  ores,  drives  our  factories  and  transports  us  from  place 
to  place  on  sea  and  land.     It  figures  at  both  ends  of  the 
electric  light.     At  one  end  it  drives  the  engine  that 
generates  the  electricity,  and  at  the  other  gives  out  the 
light  by  means  of  the  carbon  points. 

3.  In  this  last  respect  it  most  resembles  the  function 


PROOFS.  261 

of  carbon  in  the  sun.  The  electric  light  is  by  far  the 
nearest  approach  that  has  been  produced  on  the  earth 
to  the  dazzling  light  of  the  sun,  which  it  much  resem- 
bles. The  particles  of  carbon  as  it  may  be  supposed  to 
exist  in  the  vapor  or  atomic  dust  of  the  photosphere, 
certainly  possess  the  peculiar  quality  of  radiating  light 
and  heat  to  a  wonderful  degree,  and  seem  precisely 
adapted  to  produce  the  effects  which  we  observe  in  the 
photosphere. 

4.  If  we  reject  carbon  from  this  position  and  func- 
tion, with   what   material   wrill   we   supply  its   place? 
Neither  the  vapor  of  iron  nor  any  other  metal  is  avail- 
able, because  these  metals  are  proved  to  be  transpar- 
ent gases  in  the  stratum  overlaying  the  photosphere, 
whereas  the  latter  is  an  aggregation  of  opaque  fiery 
clouds.     Probably  the  only  remaining  substance  that  is 
not  volatilized  and  sent  to  the  upper  regions  of  the  sun's 
atmosphere  is  silicon.     But  this  has  never  exhibited  any 
of  the  light  and  heat  producing  properties  of  carbon, 
and   hence  there  is  no  reason   for  assigning  it  to  this 
place. 

5.  Nature  always  employs  the  means  best  adapted 
to  secure  her  ends.     The  photosphere  ought,  to  be  and 
is,  above  all  other  forms  of  matter,  the  greatest  radiator 
of  light  and  heat.     But  a  good  radiator  of  heat  must  of 
necessity  be  an  equally   good   absorber.     In   both  of 
these  respects,  carbon  is  unequalled.     But  the  sun  can 
only  receive  heat  from  without  by  radiation  from  other 
suns.     If  the  sun's  radiant  heat  came  from  within  its 
own  body,  not  only  would  it  speedily  be  exhausted,  but 
the  photosphere,  by  means  of  which  this  heat  is  radi- 
ated into  space,  would  be  the  coldest  and  darkest  part 


262  SUN  SPOTS. 

of  the  sun,  instead  of  being  the  seat  of  his  most  intense 
heat  and  light. 

6.  It  may  be  inquired :  If  the  whole  photosphere  is 
glorified  incandescent  carbon,  in  fact,  literal  diamond 
dust,  why  does  it  not  show  itself  by  means  of  the  spec- 
troscope 2  I  reply  that  the  spectroscope  gives  but  three 
kinds  of  spectra :  the  continuous  spectrum  of  incandes- 
cent solids  and  liquids;  the  bright-lined  spectra  of 
incandescent  gases,  and  the  dark-lined  spectra  of  absorb- 
ing gases.  The  condition  of  carbon  in  the  photosphere 
being  an  opaque  cloud,  is  such  as  to  give  out  only  the 
continuous  spectrum.  This  it  does,  but  marked  by  the 
absorption  lines  of  the  overlying  gases  of  iron,  sodium, 
hydrogen,  etc.  Silicon  is  invisible  in  the  sun  for  the 
same  reason.  In  fine,  it  is  not  a  matter  of  reasoning, 
but  of  fact,  that  the  most  refractory  substance  or  sub- 
stances, the  last  to  fuse  and  vaporize,  must  form  the 
core  of  the  sun.  This,  from  the  analogy  of  the  earth, 
we  should  infer  to  be  mainly  silicon. 

But  it  may  be  said  that  as  carbon  volatilized  in  the 
electric  arc,  and  even  in  the  Bessemer  furnace,  does 
give  out  bright-lined  spectra,  why  not  in  the  sun,  if  it 
exists  there? 

It  is  a  familiar  fact  that  the  more  a  gas  is  compressed 
the  more  nearly  its  spectrum  approaches  the  continu- 
ous form.  Hydrogen,  the  rarest  of  gases,  may  be  so 
compressed  as  to  yield  a  continuous  spectrum. 

The  compression  under  which  carbon  exists  in  the 
photosphere  may  well  be  amply  sufficient  to  overcome  its 
reluctant  tendency  to  exhibit  bright-lined  spectra  in  the 
spectroscope.  If  it  be  an  argument  against  the  carbonic 
constitution  of  the  photosphere  that  it  gives  no  bright 
lines  in  the  spectroscope,  it  is  an  equally  good  objection 


PROOFS. 

to  every  other  known  substance,  as  the  photosphere, 
whatever  be  its  constitution,  gives  out  110  bright-lined 
spectra,  but  the  continuous  spectrum  only. 

7.  Carbon  is  sui  generis  among  the  elements.     It 
sparkles  with  an  inherent  light  in  the  diamond.     In  the 
forms  of  wood,  charcoal,  mineral  coal  and   the  hydro- 
carbons, it  burns  readily  and  often  with  uncontrollable 
intensity ;  while  in  the  form  of  graphite,  it  is  one  of 
the  most  incombustible  of  the  elements,  and   in  all  its 
forms  it  is  infusible  at  any  degree  of  terrestrial  heat. 
But  while  infusible,  it  can  readily  be  volatilized  in  the 
electric  arc.     It  seems  to  ignore  the  liquid  state  and 
leap  at  one  bound  from  the  solid  to  a  state  nearly  re- 
sembling the  gaseous.     And  still  we  cannot  say  that  in 
this  condition  it  is  a  gas.     On  the  contrary,  it  seems  to 
be  simply  fixed  carbon,  only  infinitely  subdivided  and 
shining  with  unutterable  brightness.     It  is  in  this  form, 
as  I  conceive,  that  it  forms  the  photospheric  clouds, 
brightest  and  most  rarefied  at  the  surface,  where  it  is 
exposed  to  the  concentrated  starshine  of  all  the  suns, 
and  decreasing  in  brightness,  but  increasing  in  density 
for  thousands  of  miles  downward  to  the  nucleus  of  the 
sun. 

8.  I  need  spend  no  time  in  proving  that  the  photo- 
sphere is  not  a  transparent  gas.    Although  it  floats  in  an 
atmosphere  of  metallic  gases,  its  cloud-like  character  is 
conceded  by  all.     What  element,  except  carbon,  is  capa- 
ble  of  preserving  a  finely  divided   or  even  vaporous 
form  under  a  temperature  that  converts  iron  and  other 
metals  into  transparent  gases  ? 

Lastly,  in  the  economy  of  nature,  the  peculiar  func- 
tion of  carbon  seems  to  be  the  reception  and  radiation 
of  heat,  while  that  of  ether  seems  to  be  its  rapid  con- 


264  SUN*  SPOTS. 


veyance  from  sun  to  sun  and  from  world  to  world.  On 
the  earth  heat  creeps,  walks  or  runs  according  to  the 
conducting  capacity  of  the  different  substances  on 
which  it  is  dependent  for  transmission,  but  it  flies 
through  space  on  ethereal  wings  at  the  rate  of  one  hun- 
dred and  eighty-five  thousand  miles  per  second. 


CHAPTEK  VIII. 

APPEARANCE   OF  SUN  SPOTS. 

Phosbi  tristis  imago 
Lurida  solicitis prcebebat  lumina  terris. 


—  OVID. 


TTTE  will  here  introduce  another  figure  from  Schel- 
V  V     leu's  "  Spectrum  Analysis,"  illustrating  the  ap- 
pearance of  the  sun  spots : 


FIG.  17.— SUN  SPOT  OF  JULY  30, 


This  figure  is  most  instructive.     We  can  almost  read 
in  it  the  whole  history  of  a  large  sun  spot.     It  has  evi- 


266  STJN    SPOTS. 

dently  been  a  spot  of  the  size  of  the  outer  periphery  of 
the  penumbra,  but  now  in  the  process  of  healing  up. 
Granulations  from  all  sides  are  pushing  in  toward  the 
centre,  as  if  to  close  up  a  wound  inflicted  on  the  sun  by 
his  own  ungrateful  children. 

The  enormous  size  of  many  of  the  sun  spots  is  incon- 
sistent with  the  idea  that  they  are  produced  by  the  splash- 
ing of  falling  meteors.  Our  earth,  if  dropped  into  some 
of  these  cavities,  would  be  like  a  pebble  dropped  into  the 
crater  of  a  volcano.  Bodies  of  that  size  could  easily  be 
observed  if  such  were  falling  into  the  sun.  Besides, 
their  absence  from  the  firmament  would  quickly  'be 
noted  by  our  eagle-eyed  astronomers.  Still  less  can  we 
conceive  of  eruptions  covering  millions  of  square  miles. 
In  fact  the  appearance  of  the  spots  resembles  nothing 
we  can  conceive  of  so  much  as  the  condensation  and 
precipitation  of  large  areas  of  solar  clouds  in  conse- 
quence of  changes  in  the  solar  weather,  quite  analogous 
to  what  we  see  on  the  earth,  wrhere  clouds  covering  large 
districts  frequently  condense  and  disappear  in  a  few 
hours.  The  edges  of  these  precipitated  clouds  would 
naturally  be  grandly  jagged  like  those  of  the  silver- 
capped  thunder  heads  that  sometimes  adorn  our  sum- 
mer skies,  only  incomparably  vaster  and  brighter;  in 
one  word,  like  the  edges  of  a  sun  cloud. 

But  a  change  of  weather  in  the  sun,  as  upon  the 
earth,  means  a  change  in  temperature.  Our  changes 
come  from  the  sun.  The  sun's  changes  must  come  from 
other  heavenly  bodies.  The  sun,  vast  as  is  his  mass,  can 
no  more  originate  changes  in  his  own  temperature  or 
weather  than  the  earth.  If  he  w^ere  wholly  isolated 
from  all  extra-solar  influences,  his  own  heat  would  very 
soon  be  equally  diffused  throughout  his  entire  mass,  and 


APPEARANCE   OF   SUN   SPOTS.  267 

all  activity  would  cease.  It  is  only  by  interaction  and 
interchange  among  celestial  bodies  that  the  eternal 
round  is  kept  up,  which  forms  the  life  of  the  world. 

The  edges  of  these  sun  spots,  thousands  of  miles  in 
depth,  sometimes  take  on  the  appearance  of  cyclones 
produced  by  the  clashing  currents  in  the  photospheric 
clouds,  as  elsewhere  explained.  Generally,  however,  as 
the  sun's  heat  arrives  and  departs  from  all  parts  of  his 
surface  almost  equally,  the  clouds  will  be  comparatively 
calm,  and  a  sun  spot,  once  formed,  will  be  likely  to 
remain  for  a  considerable  time.  The  wreathen  vapors 
around  the  edges  and  projecting  into  the  abyss  seem  to 
take  on  the  fantastic  forms  of  beauty  with  which  nature 
delights  to  amuse  herself  in  her  idle  hours,  more  akin 
to  cumulus  clouds,  lazily  sunning  themselves  in  our  calm 
summer  skies,  than  to  the  rude  shocks  of  storm  and 
tempest.  The  fringes,  plumes  and  sprays  that  charac- 
acterize  some  of  the  sun  spots,  resembling  the  arbores- 
cent and  fern-like  tracings  of  frost  work  upon  glass,  are 
finely  delineated  in  another  of  Prof.  S.  P.  Langley's  illus- 
trations. This,  on  account  of  its  size,  we  are  obliged  to 
divide.  The  other  half  will  be  introduced  as  Fig.  21. 

Another  peculiar  appearance  in  the  sun  spots  may 
perhaps  be  explained  upon  this  theory.  I  refer  to  the 
grandly  corrugated  or  channelled  appearance  of  the 
sides,  as  if  raked  downward  by  Neptune's  trident.  If 
the  body  of  the  spots,  so  to  speak,  is  produced  by  con- 
densations of  great  areas  of  fiery  clouds,  then  we  may 
suppose  that  the  edges  of  these  spots  are  in  a  condition 
of  partial  condensation,  and  therefore  denser  than  the 
surrounding  photospheric  clouds.  These  partially  con- 
densed bordering  clouds  might  be  expected  to  roll  or 
glide  down  the  declivities  of  the  sun  spots,  and  the  pe- 


268 


SUN    SPOTS. 


culiar  manner  in  which  the  sun  is  supposed  to  receive 
his  light,  not  in  parallel  rays  as  from  one  sun,  but  in  all 
directions,  would  show  these  avalanches  as  bright  at  the 
bottom  as  at  the  top. 

Again ;  these  vast  descending  avalanches  of  partially 


FIG.  18.—  SUN  SPOT  or  MARCH  5,  1873.—  BY  PROF.  S.  P.  LANGLEY. 

cooled  solar  clouds  would,  on  reaching  the  nucleus,  be 
arrested  and  swell  out  or  bulge  into  those  club-shaped 
forms  observed  at  the  bottom  of  the  sun  spots;  and, 
moving  horizontally  toward  the  centre,  they  would  ulti- 
mately cover  the  bottom  and  completely  fill  up  the  cav- 


BOILING    APPEARANCE    OF    SUN    SPOTS.  269 

ity.  Owing  to  the  rounded  or  club  form  of  these  ava- 
lanches at  the  bottom,  and  the  cross  fire  of  the  light  by 
which  they  are  seen,  they  will  appear  highly  luminous, 
especially  so  by  contrast,  so  long  as  any  portion  of  the 
floor  remains  uncovered. 

BOILING    APPEARANCE    OF    SUN    SPOTS. 

Anyone  who  has  watched  what  is  called  the  boiling 
action  at  the  bottom  of  these  spots  must  have  the  most 
intense  interest  and  curiosity  awakened  to  know  the 
cause  of  this  most  interesting  phenomenon. 

The  boiling  appearance  harmonizes  admirably  with 
the  theory  here  advanced.  If  the  photosphere  is  com- 
posed of  intensely  heated  carbon  dust  or  mist,  and  the 
spots  are  immense  openings  in  the  same,  caused  by  the 
partial  cooling  and  condensation  of  this  substance,  then 
this  condensed  and  precipitated  material  will  be  much 
darker,  .as  well  as  cooler,  than  the  surrounding  photo- 
sphere. In  fact,  in  comparison  with  the  photosphere, 
the  spots  appear  perfectly  black.  This  darker  precipi- 
tated matter  covering  the  umbra  or  nucleus,  is  immedi- 
ately exposed  to  the  starshine  of  the  heavens.  It  will 
gradually  reabsorb  heat,  and  will  almost  literally  boil 
up  from  the  bottom.  This  process  will  continue  till  this 
matter  has  attained  the  temperature  of  the  surrounding 
photosphere  and  filled  the  cavity  with  the  newly  formed 
clouds.  The  process  is  slightly  analogous  to  what  we 
sometimes  witness  upon  the  earth  when  the  whole  heav- 
ens are  covered  by  thick  layers  of  cloud.  These,  by 
cooling,  condense  to  rain  and  fall  to  the  ground,  cover- 
ing its  surface  with  a  plentiful  moisture.  Then  comes 
out  a  hot  sun  and  vaporizes  this  moisture,  and  in  a  short 
time  the  sky  is  again  covered  with  fleecy  clouds.  This 


270  SUN  SPOTS. 

boiling  action  of  the  sun  spots,  like  a  boiling  pot,  com- 
mences at  the  edges  or  penumbra  where  the  photo- 
spheric  clouds  have  been  only  partially  cooled,  and  there- 
fore soonest  recover  the  normal  temperature  of  the 
photosphere. 

FACUluB. 

I  desire  to  notice  only  one  more  of  the  phenomena 
attending  sun  spots,  and  that  is  the  faculee  or  bright 
ridges  that  frequently  surround  the  spots.  These,  by 
some  of  the  advocates  of  the  eruptive  theory  are 
ascribed  to  the  splashing  upward  of  the  photospheric 
material  by  the  downpour  of  the  cool  eruptions. 

There  are  at  least  three  objections  to  this  view.  One 
is,  that  it  is  inconceivable  that  a  single  eruption  could 
be  of  such  enormous  dimensions  as  some  of  these  spots 
present.  Another  is,  that  explosive  eruptions  of  such 
extent  and  violence,  if  they  existed,  would  tear  up  the 
photosphere  in  the  wildest  and  most  disordered  forms, 
instead  of  the  gently  sloping  and  channelled  edges  of 
the  penumbra,  with  its  arborescent  sprays  and  fern-like 
fringes.  Lastly,  and  most  conclusively,  if  these  spots 
were  caused  by  explosive  eruptions,  the  ejected  matter 
would  fall  back  almost  as  soon  as  expelled,  and  the  sea 
of  fire  would  close  over  the  crater  as  quickly  as  if  it 
were  water  on  the  earth.  If,  on  the  contrary,  these 
spots,  continental  in  theii1  dimensions,  are  caused  by 
climatic  changes,  which  even  on  the  earth  often  extend 
through  many  days,  we  may  reasonably  expect  the  same 
to  occur  in  the  sun.  Such  we  find  to  be  the  fact. 

Now,  on  this  hypothesis,  we  should  expect  the  upper 
edges,  or  the  margins  of  the  sun  spots,  to  be  much 
brighter  than  the  general  surface  of  the  photosphere, 


^E.  271 

just  as  the  umbo  or  liighest  point  of  a  rounded  gilt 
button  is  always  dazzlingly  briglit,  while  the  rest  is 
relatively  dull.  So  the  edges  of  the  deep  cavity  caused 
by  cooling,  condensation,  and  precipitation,  must  neces- 
sarilv  stand  out  more  prominently  in  consequence  of 
the  caving  in,  so  to  speak,  of  the  sun  spot.  These 
edges,  thus  left  prominent,  may  account  for  the  faculse 
around  the  spots.  This  is  grandly  illustrated  in  the 
edges  of  the  magnificent  summer  clouds  that  form  the 
rocky  mountains  of  our  western  skies.  This  feature  is 
well  illustrated  by  Fig.  19. 


FIG.  19.— FROM  SCHELLEN'S  "SPECTRUM  ANALYSIS." 

But  not  infrequently  spots  appear  surrounded  by 
literal  mountains  of  light.  This  is  just  what  might  be 
expected  on  the  theory  here  advocated.  A  valley  in 
an  Alpine  region  of  the  sun  is  unlike  a  valley  similarly 
situated  on  the  earth.  In  the  latter  case  the  valley  will 
be  hotter  than  the  surrounding  mountains.  It  will 
receive  just  the  same  amount  of  heat  by  radiation,  both 
the  mountain  and  the  valley  being  shaded  on  one  side 
when  the  sun's  rays  are  oblique,  and  both  receiving  his 
full  radiance  when  the  rays  are  vertical.  But  in  the 
case  of  the  terrestrial  mountain,  the  heat  is  reflected 


272 


SUX    SPOTS. 


away,  while  in  the  case  of  the  valley,  it  is  reflected  from 
side  to  side,  and  nearly  all  retained. 

In  the  sun  the  valleys  are  coolest,  because  the  star- 
shine  comes  in  all  directions,  and  much  of  it  being 
received  on  the  sides  and  summits  of  the  towering 
faculae,  is  cut  off  from  the  valleys  between,  which  are 
therefore  relatively  cooler  than  the  rest  of  the  photo- 
sphere, and  therefore  more  likely  to  become  the  thea- 
tres of  sun-spot  action. 


FIG.  -20.— FACULAE  AND  SUN  SPOTS,  BY  CHACERNCE. 

This  is  illustrated  by  Fig.  20,  from  Schellen's  "  Spec- 
trum Analysis." 


GRANULES   AND   PORES. 


One  of  the  most  convincing  arguments  of  the  truth 
of  this  theory  of  sun  spots  to  the  mind  of  the  writer, 
may  be  stated  thus  : 

Those   who  have  examined  the  solar  surface  most 


GRANULES    AND    POKES.  273 

carefully,  with  the  best  facilities,  and  under  the  most 
favorable  circumstances,  find  that  the  surface,  though 
we  seek  in  vain  for  words  to  express  its  intensity  of 
light  and  heat,  is  not  of  uniform  brightness.  It  is 
mainly  made  up  of  what  are  called  granules  and  pores, 
or  alternate  specks  of  light  and  shade,  though  even 
these  granules  are  often  100  miles  in  diameter,  and  the 
pores  much  larger.  These  granules  and  pores  resemble 
rice  grains  floating  in  a  lake  of  ink ;  or,  perhaps,  a 
better  illustration  would  be  a  western  landscape,  seen 
at  a  little  distance,  at  the  moment  when  the  first  snow 
flakes  of  winter  have  scarcely  half  covered  the  black 
soil  of  our  prairies.  According  to  the  law  which  makes 
brightness  proportioned  to  heat  in  a  radiant  body,  the 
granules  represent  the  most  highly  heated,  and  the 
pores  the  relatively  cooler,  portions  of  the  photosphere. 
In  other  words,  the  granules  are  little  faculas,  and  the 
pores  little  sun  spots.  These  granules  and  pores  are 
coextensive  with  the  sun's  surface,  and  are  not  confined 
to  the  maculated  zones.  These  pores  are  caused,  as  I 
believe,  by  the  enormous  amount  of  heat  constantly 
radiated  by  the  sun,  which  cannot  fail  to  lower  rapidly 
the  temperature  of  the  solar  surface.  If  the  sun  re- 
ceived no  increments  of  heat  at  his  surface,  his  whole 
face  would  speedily  turn  to  blackness.  He  could  not 
wait  for  heat  to  be  supplied  by  the  slow  processes  of 
conduction  or  convection  from  an  inexhaustible  foun- 
tain at  his  centre,  even  if  we  conceded  its  existence. 
But  it  would  be  just  as  impossible  to  manufacture  heat 
from  nothing  at  the  centre  of  the  sun  as  to  manufacture 
matter  in  the  same  way.  Instantaneous  radiation 
requires  an  instantaneous  supply.  An  infinite  amount 
sent  forth  demands  an  infinite  amount  returned,  and 
18 


274  SUN  SPOTS. 

the  rapidity  of  one  operation  precisely  measures  that 
of  the  other. 

If  these  pores  are  little  sun  spots  caused  by  cooling 
and  precipitation  by  radiation  from  small  areas  of  the 
photosphere,  we  have  only  to  suppose  this  cooling  to  be 
slightly  increased  from  any  cause  in  the  maculated 
belts  to  account  for  the  enlarged  areas  of  cooling  and 
precipitation  called  sun  spots. 

I  need  not  say  where  J  would  look  for  this  cause, 
to-wit  :  to  the  shadows  cast  by  Jupiter  and  the  lesser 
planets  upon  the  sun. 

This  theory  also  accords  beautifully  with  the  small 
beginnings,  slow  growth,  and  long  duration  of  sun 
spots.  James  Carpenter  says :  "  The  first  symptom  of 
a  spot  appearing  is  a  tiny  speck  upon  the  photosphere. 
This  goes  on  enlarging,"  etc.  Such  a  beginning  and 
evolution  are  compatible  with  neither  a  meteoric  nor 
an  eruptive  cause.  If  they  were  produced  by  the 
splashing  of  bodies  of  the  size  of  the  earth,  or  even 
Jupiter  (for  the  diameters  of  some  of  these  spots  far 
exceed  that  of  Jupiter),  they  would  not  commence  at 
a  point  and  gradually  enlarge.  Neither  would  they 
continue  for  weeks  and  months  with  only  slight  changes 
in  form  and  size. 

This  argument  is  equally  good  as  against  the  erup- 
tive theory,  and  seems  to  be  conclusive  against  both. 
A  gaseous  eruption  would  burst  forth  with  suddenness 
and  violence,  of  full  dimensions,  and  the  displaced  pho- 
tosphere would  fall  back  to  its  place  as  soon  as  the 
eruption  ceased. 

The  writer  would  not,  of  course,  deny  the  existence 
of  immense  eruptions  in  the  sun.  But  these  are  mainly 
in  the  chromosphere,  corona,  and  upper  atmosphere. 


GRANULES    AND    PORES. 


275 


Eruptions  in  the  photosphere,  so  far  as  he  can  learn,  are 
hypothetical  only. 

The  point  to  which  the  writer  desires  to  call  the  atten- 
tion of  those  who  are  in  search  of  truth  for  its  own 
sake,  is  this,  that  the  spots  commence  in  points,  and 
open  out  more  or  less  gradually,  often  to  continental 
dimensions,  which  they  sometimes  retain  for  months. 


FIG.  21.— SUN  SPOT  OF  MARCH  5,  1873.— BY  PROP.  S.  P.  LANOLEY. 

We  here  introduce  the  other  half  of  one  of  Prof. 
Langley's  illustrations,  both  for  the  purpose  of  showing 
the  club-shaped  projections  into  the  cavity  and  the 


276  SUN  SPOTS. 

relative  size  of  one  of  these  spots  compared  with  the 
Western  Hemisphere  of  the  earth,  shown  in  the  upper 
left-hand  corner.  If  the  original  spot,  as  seems  to  me 
probable,  was  co-extensive  with  the  outer  edge  of  the 
penumbra,  it  will  be  seen  at  a  glance  how  improbable 
it  would  be  that  the  spot  could  be  caused  by  either  a 
meteor  or  an  eruption.  If  the  meteor  were  of  the  size 
of  the  earth,  it  would  be  lost  in  the  cavernous  depth  of 
one  of  these  ( spots. 

Neither  a  meteor  of  sufficient  size,  nor  an  eruption 
of  sufficient  extent,  to  produce  such  a  spot,  could  com- 
mence with  a  point  aiid  enlarge  to  billions  or  even  mill- 
ions of  square  miles.  But  if  the  photosphere  through- 
out its  whole  extent  and  in  its  normal  condition  is 
honeycombed  with  little  sun  spots,  caused  by  the  cool- 
ing from  radiation,  then  it  needs  but  a  slight  additional 
cooling  in  the  maculated  belts  to  cause  first  the  coales- 
cence of  a  few  neighboring  spots  and  -then  their  exten- 
sion to  large  areas. 

The  theory  of  sun  spots  here  advanced  also  harmon- 
izes with  one  of  nature's  sublimities;  the  sublimity  of 
the  minute.  Nature  is  sublime  in  the  smallness  of  her 
atoms ;  in  the  minuteness  of  her  microscopic  and  ultra 
microscopic  organisms,  and  often  in  the  feebleness  of 
her  forces.  The  force  of  gravitation  acting  on  the 
earth  is  so  weak  that  it  only  pushes  the  earth  about  one- 
tenth  of  an  inch  toward  the  sun,  while  the  tangential 
force  carries  it  nearly  nineteen  miles  forward.  But 
the  cooling  shadows  that  cause  the  sun  spots  are  the 
exact  counterpart  of  gravitation  on  the  earth.  This 
shows  how  small  a  change  is  required  to  enlarge  the 
small  spots  or  pores  into  the  larger  ones.  It  also  shows 
why  the  maculated  belts  are  almost  never  free  from 


GRANtTLES    AND    PORES.  277 

spots,  because  the  planets  even  at  their  aphelia  cast 
slightly  cooling  shadows  on  the  sun.  If  the  breaking  out 
of  these  spots  be  attributable  to  a  lowering  of  the  tem- 
perature in  the  maculated  belts,  and  I  do  not  see  how  it 
is  possible  to  doubt  it,  in  view  of  their  darker  color  and 
lower  temperature,  then  it  is  manifest  that  the  photo- 
sphere within  those  belts,  notwithstanding  its  intense 
heat,  is  at  the  turning  point,  so  to  speak,  between  the 
condition  of  the  bright  granules  and  the  darker  pores, 
with  the  advantage  rather  on  the  side  of  the  pores. 
These,  according  to  Prof.  Langley,  occupy  four-fifths  of 
the  sun's  surface,  but  emit  only  one-fourth  of  his  light 
and  heat. 


CHAPTER  IX. 

RECAPITULATION. 

Line  upon  line,  precept  upon  precept.— BIBLE. 

FIRST.  It  is  a  matter  of  fact  and  not  of  conjecture 
that  Jupiter  and  the  other  planets  intercept  and 
shut  off  from  the  sun  a  portion  of  the  light  from  a  large 
Held  of  the  starry  concave.  If  the  stars  send  forth  rays 
of  energy  capable  of  being  turned  to  heat  at  the  sur- 
face of  the  sun,  then  the  sun  will  be  deprived  of  so 
much  heat  as  represents  the  intercepted  rays  of  me- 
chanical motion  convertible  into  heat, 

2.  The  sun's  photosphere  is  generally  believed   to 
be  composed  of  incandescent  metallic  vapors  (I  have 
suggested  carbon  vapors),  floating  in  an  atmosphere  of 
metallic  gases. 

3.  It  is  by  much  the  hottest  portion  of  the  sun.    This 
is  shown  first,  by  actual  experiment  by  Prof.  Langley 
and  others ;  second,  by  its  surpassing  brilliancy,  the  tem- 
perature of  elementary  substances  being  invariably  in 
proportion  to  their  brightness  or  capacity  for  emitting 
light ;  and  third,  by  analogy  of  other  celestial  bodies ; 
e.g.,  the  Earth  and    other  planets,  especially  Jupiter, 
exhibit  unmistakable  evidence  of  a  common  origin  and 
nature  with  the  sun.     These  all  receive  and  part  with 
their  commercial  or  exchangeable  heat  at  their  ports  of 
entry.     These  ports  embrace  their  whole  exterior  sur- 
face in  contact  with  the  ethereal  ocean,  by  means  of 

278 


RECAPITULATION.  279 

which  the  imports  and  exports  of  their  foreign  com- 
merce in  the  different  forms  of  energy  are  exchanged: 
The  sun  is  the  great  entrepot  of  this  commerce  in  our 
system  where,  as  I  think,  mechanical  motion  is  ex- 
changed for  light  and  heat,  the  fixed  capital  or  internal 
heat  of  all  these  bodies  remaining  unchanged  from  age 
to  age. 

4.  As  the  sun's  photosphere  is  hotter  than  the  nu- 
cleus, it  cannot,  either  by  conduction  or  convection, 
receive  this  excess  from  the  interior,  and  consequently 
must  receive  it  through  the  ether  from  the  starry  con- 
cave. 

5.  Jupiter  and  the  other  planets  are  the  only  bodies 
which   can   possibly  intercept   the  energy  convertible 
into  heat,  coming  from  the  celestial  concave. 

6.  These  shadows  are  wholly  penumbral  and  exceed- 
ingly thin,  as  the  light  and  heat  from  almost  the  entire 
starry   concave    shines    over,   under    and    around   the 
planets.     Still  these  shadows  are  not  infinitesimal  in 
their  influence.     It  is  easy  to  see  without  a  diagram 
that  a  portion  of  the  wave  motion,  or  energy  converti- 
ble into  heat,  from  a  large  circle  in  the  starry  vault  is 
intercepted  from  the  sun  by  each  of  the  planets. 

7.  The    inclination    of    the    sun's    equator    to    the 
ecliptic,  by  increasing  the  extreme  solar  latitude  north 
and  south,  of  all  the  planets,  widens  the  shaded  or 
maculated  zones.     This  can  be  readily  seen  from  Fig. 
15.     The  central  part  part  of  this  zone  on  both  sides  of 
the  equator  is  given  up  as  the  arena  for  the  perpetual 
battle  of  the  giants  in  the  form  of  photospheric  clouds 
from  both  the  north  and  south,  where  they  meet  in  con- 
flict, and  the  ranks  of  both  sink  vanquished  to  unknown 
depths  below.     In  the  melee  of  this  conflict  the  clouds 


280  SUN    SPOTS. 

are  too  much  agitated  to  admit  of  the  formation  of  sun 
spots,  as  these  require  a  comparatively  undisturbed  con- 
dition of  the  photosphere  in  which  they  can  slowly 
develop  and  retain  their  forms,  sometimes  for  months, 
with  only  slight  changes.  The  necessary  result  will  be 
two  "spotty"  belts,  which  we  might  almost  predict  a 
priori  would  be  found  mainly  between  the  parallels  of 
ten  degrees  and  thirty  degrees  of  north  and  south  lati- 
tude. 

This  corresponds  wonderfully  with  the  distribution  of 
the  sun  spots. 

8.  Sun  spots  must  of  necessity  be  produced  by  some 
dynamic  change,  and  doubtless  of  that  form  which  we 
call  heat.    In  other  words,  by  an  excess  or  deficiency  of 
heat.     If  it  were  an  excess,  the  photospheric  clouds  in 
these  belts  would  become  brighter,  if  that  were  possible. 
But,  as  the  spots  appear  to  dissolve  and  turn  to  black- 
ness, it  must  be  a  deficiency,  instead  of  a  redundancy, 
of  heat  which  produces  the  spots. 

9.  To   the   shadows   of   the   planets   alone  can  we 
look  for  this  cooling  influence  upon  the  maculated  zones 
of  the  sun.     There  are  no  other  intervening  bodies. 

10.  As  all  the  forms  of  cosmic  energy  are  correlated 
and  interchangeable ;  and  as  a  portion  of  this  energy, 
exactly   proportioned    to    the    mass    of     each    planet 
divided  by  the  square  of  its  distance,  is  intercepted  from 
the  sun  and  expends  itself  upon  the  planets  themselves, 
and  as  this  is  the  exact  expression  for  gravitation,  who 
can  doubt  that  the  intercepted  energy  is  identical  with 
gravitation  and  constitutes  the  centripetal  forces  of  all 
the  planets  ? 

11.  The  sun  spots  appear  to  have  a  certain  degree 
of  periodicity,  but  not  sharply  defined,  either  as  to  the 


RECAPITULATION.  281 

amount  of  variation  or  the  times  of  the  apparent  max- 
imum and  minimum  periods.  The  variations  in  these 
spots  are  much  like  the  vicissitudes  of  the  weather  on 
our  earth,  and  produced  by  similar  causes.  The  seasons 
return  with  certainty,  but  variable  as  to  the  degrees  of 
heat  and  cold,  and  also  in  being  earlier  or  later  within 
certain  limits.  The  grand  average,  however,  is  always 
the  same.  It  is  the  same  with  the  sun  spots.  The  aver- 
age for  a  long  series  is  very  nearly  uniform,  being 
nearly,  if  not  exactly,  11.86  years,  which  is  the  period 
of  Jupiter's  annual  revolution  from  perihelion  to 
perihelion.  Now  Jupiter's  mass  is  three  hundred  and 
thirty-eight  times  that  of  the  earth,  and  more  than 
double  that  of  all  the  other  planets  combined.  His 
mean  distance  from  the  sun  is  much  less  than  the  mean 
of  the  other  major  planets.  His  eccentricity  is  such  that, 
at  his  perihelion,  he  is  forty -five  million  miles  nearer  to 
the  sun  than  at  his  aphelion.  The  effect  of  this  combi- 
nation of  facts  is  such  that  the  planet  Jupiter,  if  the 
theory  of  sun  spots  here  advanced  is  correct,  must  dom- 
inate both  as  to  the  amount  and  the  periodicity  of  the 
spots,  although  the  other  planets  sometimes  co-operate 
with,  and  at  others  antagonize,  his  influence,  so  far  as 
the  dates  of  the  maximum  and  minimum  periods  are 
concerned ;  and  this  fact  contributes  to  the  apparent 
irregularity  in  the  periodicity  of  the  sun  spots. 

12.  The  heating  of  the  air  at  the  equator  and  cool- 
ing it  at  the  poles  of  the  earth  cause  a  constant  circula- 
tion of  currents  from  the  equator  toward  the  poles  and 
back.  These  currents,  however,  are  regular  only  in 
their  irregularity.  The  exceptions  almost  constitute  the 
rule  in  the  case  of  the  terrestrial  currents,  owing  to  the 
variations  in  isothermal  lines  upon  the  earth,  the  differ- 


282  SUN  SPOTS. 

ence  in  temperature  of  continents  and  oceans,  the  differ- 
ence in  friction  between  land  and  water,  and  other 
causes  existing  on  the  earth  which  do  not  exist  in  the 
sun. 

If  the  sun's  photosphere  is  slightly  cooler  at  or  near 
the  equator  than  at  his  poles,  it  will  cause  a  correspond- 
ing system  of  slow  and  gentle  current*  toward  the  poles 
and  back  again,  but  in  reverse  order,  compared  with  the 
terrestrial  currents.  The  lower  currents  will  be  the 
cooler  and  the  upper  ones  the  hotter.  The  lower  ones 
will  be  accelerated  relatively  to  the  sun's  surface  in  pro- 
portion as  they  recede  from  the  equator.  The  upper 
ones,  on  the  contrary,  will  be  retarded  relatively  to  the 
sun's  surface  in  proportion  to  their  distance  north  and 
south  of  the  equator.  The  inevitable  result  of  this  will 
be  that  spots  or  openings  in  the  upper  photosphere  will 
keep  pace  with  the  rotary  motion  of  the  sun  at  his 
equator,  but  will  drag  behind  more  and  more  as  they 
increase  in  latitude,  precisely  as  we  find  the  fact  to  be. 

It  is  due  to  the  writer  also  to  remember  that  no  claim 
is  here  set  up  to  anything  like  absolute  regularity  of 
operation  in  these  hypothetical  photospheric  currents. 
A  resemblance  in  the  principle  is  all  that  is  claimed. 

13.  In  analogy  with  our  seasons,  the  maximum  of 
sun  spots  almost  always  occurs  after  the  sun  has  been 
for  some  time  exposed  to  the  cooling  influence  of  Jupi- 
ter's most  effective  shadows. 

The  planet  Jupiter  has  been  mentioned  in  connec- 
tion with  sun  spots  by  almost  every  writer  on  the 
subject,  but  only  to  discredit  the  idea  that  he  could 
exert  any  agency  in  producing  them;  and  the  idea 
that  he,  with  the  other  planets,  produces  these  spots  by 


RECAPITULATION.  283 

casting  cooling  shadows  upon  the  sun  is,  so  far  as  T  am 
aware,  a  novel  one. 

From  all  these  facts  and  coincidences  and  the  rea- 
soning by  which  they  are  connected,  I  trust  I  have 
made  a  case  worthy  of  consideration  of  the  distin- 
guished men  of  our  day  who  hold  the  keys  of  knowl- 
edge. That  they  will  give  it  a  candid  and  impartial 
consideration  I  know,  and  to  the  decisions  of  exact  sci- 
ence I  will  bow  with  submission. 


CHAPTER   X. 

UNITY    OF    THE     PROPOSITIONS    CONCERNING    SOLAR 
HEAT,   GRAVITATION,  AND  SUN   SPOTS. 

Have  you  not  heard  it  said  full  ot't'?— SHAKESPKARK. 

IDESIEE  to  repeat  for  the  sake  of  emphasis,  the 
proposition  that  the  photosphere  is  by  far  the  hot- 
test part  of  the  sun.     This  proposition,  if  my  argument 
is  sound,  is  sustained  by  two  infallible. proofs. 

1.  The  ineffable  and  incomparable  brightness  of  the 
photosphere,  which  is  the  unfailing  index  of  ineffable 
and  incomparable  heat. 

2.  The  actual  and  accurate  determinations  of  Prof. 
Langley  and  others,  which  no  one  questions,  showing 
that   the   photosphere  is  nearly  twice   as   hot   as   the 
umbra  or  nucleus  of  the  sun. 

This  being  conceded,  all  the  main  conclusions  herein 
advocated  follow  almost  inevitably.     For  example : 

1.  The  celestial  source  of  solar  heat  seems  absolutely 
certain.     The  photosphere,  notwithstanding  its  cooling 
by  radiation,  being  nearly  twice  as  hot  as  the  interior, 
certainly  cannot  derive  its  heat  from  this  interior.     It 
must  therefore  come  from  without,  that  is,  from  the 
celestial  concave. 

2.  It  is  almost  equally  certain  that  gravitation  is 
cosmic  in  its  source,  having  its  origin  in  propulsive 
mechanical  vibrations  from  the  stellar  concave.     The 
mutual  interception  of  such  rays  is  apparently  the  only 

284 


UNITY    OF   THE    PROPOSITIONS.  285 

possible  mode  in  which  lines  of  least  resistance  can  be 
established  and  maintained  in  the  heavens.  The  sun 
shuts  off  a  part  of  these  rays  from  the  earth  and  the 
earth  from  the  sun,  making  a  line  of  least  resistance  for 
both,  in  which  each  seeks  to  approach  the  other.  But 
all  forces  with  which  we  are  familiar,  manifest  them- 
selves by  motion  in  the  direction  of  the  least  resistance, 
and  doubtless  gravitation  does  the  same.  The  motions 
of  the  earth,  both  rotary  and  translatory,  date  back  to 
the  eddies  and  swirls  of  primeval  nebular  matter.  The 
sun  and  earth  are  not  tied  together  by  a  strong  cable 
attached  to  each,  but  rather,  speaking  figuratively ,  by 
twro  invisible  hands,  gently  pressing  them  together. 
These  invisible  hands  are  the  invisible  pulsations  of  the 
invisible  ether,  with  which  the  whole  heavens  are  filled, 
coming  from  opposite  points  of  the  starry  dome.  The 
sun  intercepts  from  each  molecule  in  the  earth  as  many 
of  these  pulsations  or  rays  of  mechanical  force  as  there 
are  molecules  in  the  sun,  not  one  more  nor  less.  The 
earth  does  the  same  thing  by  the  sun,  so  that  in  each 
case  gravitation  is  represented  by  the  product  of  the 
masses  of  each  divided  by  the  square  of  the  distance, 
and  the  two  bodies  present,  each  to  the  other,  a  line  of 
motion  in  the  direction  of  the  least  resistance  in  which 
they  will  seek  to  approach  each  other,  but  balanced  and 
modified  by  other  motions  in  other  lines. 

3.  Lastly,  sun  spots  being  cooler  than  the  photo- 
sphere, and  the  heat  of  the  latter  coming  down  from  the 
solar  sky  in  all  directions,  it  would  seem  that  the  spots 
must  certainly  result  from  the  interception  from  the 
maculated  belts  of  a  part  of  this  fiery  downpour.*  But 

*  It  must  always  be  borne  in  mind  that,  according  to  the  thfory  here  advo- 
cated, the  incoming  waves  are,  as  Prof.  Daniels  shows,  in  the  form  of  mechan- 
ical force  until  they  are  arrested  by  the  sun  and  turn  10  waves  of  heat. 


286  SUN  SPOTS. 

the  only  screens  interposed  between  these  belts  and  the 
celestial  sources  of  solar  heat,  are  the  planets  and  satel- 
lites of  the  solar  system.  Each  of  these  three  grand 
propositions  throws  light  upon  and  confirms  the  others. 


CHAPTEE    XI. 

IF. 
Much  virtue  in  an  if. —  SHAKESPEARE. 

IF  the  photosphere,  which  is  the  only  portion  of  the  sun 
ordinarily  visible  to  us,  except  the  glimpses  of  the 
nucleus  which  we  sometimes  catch  through  the  sun-spot 
openings,  were  simply  a  luminous,  cloud-like  envelope, 
without  proper  motion  of  its  own,  it  would  most  cer- 
tainly accommodate  itself  to  the  motion  of  the  nucleus 
and  move  with  it  throughout  its  entire  surface,  and  all 
the  sun  spots  would  just  as  certainly  keep  pace  with  the 
motion  of  the  nucleus. 

If  there  is  a  continual  downpour  of  the  upper  sur- 
face of  the  photospheric  envelope  from  the  poles  toward 
the  equator,  this  upper  surface,  having  the  slow  rotary 
motion  of  the  poles  at  its  commencement,  will  inevita- 
bly drag  behind  just  in  proportion  to  its  distance  from 
the  equator. 

If  such  currents  are  actually  approaching  the  equator 
from  the  poles  in  the  upper  portion  of  the  sun's  cloudy 
envelope,  then  of  necessity  there  must  be  counter-cur- 
rents of  the  under  portion  correspondingly  accelerated 
on  leaving  the  equatorial  regions. 

If  this  circulation  exists,  amd  I  do  not  see  how  it  can 
be  doubted,  in  view  of  the  lagging  motion  of  the  sun 
spots,  then  there  certainly  is  a  cooling  process  going  on 
in  the  equatorial  regions  of  the  photosphere.  On  no 
Other  supposition  can  we  account  for  this  circulation, 

867 


288  SUN  SPOTS. 

If  there  is  such  a  cooling  process  going  on  in  this 
region,  it  must  have  a  cause. 

If  the  heat  radiated  by  the  sun  is  received,  as  ours 
is,  by  ethereal  undulations,  and  I  have  endeavored  to 
show  that  there  is  no  other  possible  source,  then  this 
cooling  of  the  photosphere  can  only  be  effected  by  inter- 
cepting a  portion  of  these  undulations.  But  certainly 
there  are  no  heavenly  bodies  interposed  between  our 
sun  and  the  stellar  concave,  except  the  planets  and  sat- 
ellites of  our  system.  What  a  wonderful  confirmation 
of  this  view  we  find  in  the  fact  that  this  cooling  pro- 
cess takes  place  right  under  the  belt  of  the  heavens  in 
which  all  the  planets  revolve! 

I  have  introduced  each  of  these  propositions  by  an  if. 
But  they  are  all  facts,  with  many  more,  tending  to  the 
same  result,  and  I  believe  they  all  fit  and  dovetail  to- 
gether in  such  a  manner  as  will,  on  full  examination, 
carry  conviction  to  every  candid  mind.  For  example : 
The  sun  spots  are  facts ;  their  periodicity  corresponding 
closely,  if  not  exactly,  to  the  Jovian  period  is  a  fact; 
their  location  under  a  belt  in  the  heavens  including  the 
zodiac  is  a  fact ;  their  lagging  motion  as  they  recede 
from  the  equator  is  a  fact ;  their  occasional  cyclonic 
action  is  a  fact;  their  cavernous  form  and  blackened 
floor,  indicating  lower  temperature,  are  facts,  as  well  as 
Langley's  actual  measurements  confirming  the  same; 
the  location  of  all  the  planets  and  satellites  in,  or  near, 
the  belt  of  the  zodiac  is  a  fact ;  the  inclination  of  the 
sun's  axis  to  the  plane  of  me  ecliptic,  bringing  the  mac- 
ulated belts  of  the  sun  more  directly  under  the  planets, 
is  a  fact ;  the  circulation  in  the  upper  and  lower  strata 
of  the  photospheric  and  umbral  clouds  I  fully  believe  I 
am  justified  in  pronouncing  to  be  a  fact,  in  view  of  the 


IF.  289 

lagging  motion  of  the  spots,  which  cannot  otherwise  be 
explained.  It  follows  that  the  maculated  belts  are  and 
must  be  relatively  cooler  than  the  rest  of  the  photo- 
sphere. 

Again,  it  follows  with  the  certainty,  as  it  seems  to 
me,  of  demonstration,  that  the  sun  spots  are  caused  by 
the  condensation  and  precipitation  of  the  photospheric 
clouds.  And  lastly,  if  I  am  right,  it  follows  with  the 
cumulative  force  of  all  these  facts  combined,  that  the 
sun  receives  his  unwasting  supplies  of  light  and  heat 
by  ethereal  undulations  at  his  surface  from  the  hollow 
sphere  of  suns  by  which  he  is  surrounded. 

No  imagination  can  possibly  form  a  conception  of 
the  Tophet  of  fire  and  flame  that  encircles  the  sun.  It 
has  no  resemblance  to  the  lurid  flames  of  Tartarus,  as 
painted  by  heathen  poets.  It  is  simply  brightness  and 
heat  in  their  most  intensified  forms.  The  energy  or 
ethereal  motion,  which  causes  the  sun's  heat,  may,  and 
probably  does,  come  down  as  calmly  and  noiselessly  as 
our  sunshine,  or  even  starshine.  It  is  not  until  these 
ethereal  vibrations  bury  themselves,  so  to  speak,  in  the 
sun's  photosphere  that  they  turn  to  heat  and  are  radi- 
ated in  that  form. 
19 


CHAPTER  XII. 

CONCLUSION. 
Let  us  hear  the  conclusion  of  the  whole  matter. —  SOLOMON. 

WITHOUT  intending  it,  and  in  spite  of  myself, 
my  thoughts  have  taken  the  form  of  a  scheme 
or  system.  I  started  out  to  commit  to  writing  a  few 
thoughts  in  regard  to  solar  heat.  But  I  found  that 
this  was  but  a  single  link  in  an  endless  chain,  and  that 
I  could  neither  comprehend  the  subject  myself  nor 
make  it  intelligible  to  others  without  following  this 
mysterious  energy  under  all  its  Protean  forms  and 
through  the  entire  circle  of  its  manifestations. 

Notwithstanding  the  feeble  and  halting  steps  by 
which  I  have  endeavored  to  trace  the  exhibitions  of 
this  energy  in  nature,  the  system  itself  is  grand  beyond 
the  powers  of  thought  or  expression. 

Of  course  the  fundamental  principle  of  the  only  true 
system  is  the  "  conservation  of  energy.' '  But  many 
writers,  with  whom  I  would  not  for  a  moment  presume 
to  compare  myself,  at  least  for  research  in  special 
departments,  seem  to  understand  this  principle  in  an 
exceedingly  limited  sense.  For  example,  it  is  not 
uncommon  for  them  to  speak  of  all  the  heat  of  the  sun, 
except  the  two  hundred  and  thirty  millionth  part,  inter- 
cepted and  utilized  by  the  planets,  as  wandering  off 
into  the  depths  of  space  and  being  lost,  forgetting  that 
heat  and  all  forms  of  energy  are  motion,  or  at  least 


CONCLUSION.  291 

manifest  themselves  by  motion.  In  the  case  of  intense 
heat,  it  is  a  rapid  vibratory  motion  of  incandescent 
matter.  But  certainly  there  can  be  no  motion  where 
there  is  no  matter.  If  the  ethereal  waves  should  ever 
arrive  at  a  point  where  there  is  no  ether  to  carry  them 
farther  and  no  material  bodies  to  arrest  them,  it  is  not 
pretended  that  they  could  longer  exist  in  any  form. 
This  would  certainly  be  their  Tarpeian  rock,  from  which 
they  would  leap  from  existence  into  annihilation.  The 
same  fate  would  await  the  doctrine  of  the  conservation 
of  energy.  Again,  this  two  hundred  and  thirty  mill- 
ionth part  of  the  heat  of  the  sun  received  by  the  earth 
and  other  planets  is  again  radiated  into  space  as  fast  as 
it  is  received,  as  the  earth  is  not  growing  hotter.  This 
is  surely  not  inconsiderable  in  amount.  But  it  is  wholly 
disregarded  by  many,  I  may  almost  say,  by  all.  Again, 
the  starry  concave  is  studded  with  millions  of  millions, 
yea  billions  of  billions,  of  suns  beyond  the  power  of  the 
imagination  to  grasp  or  of  figures  to  express.  Appar- 
ently only  an  infinitesimal  quantity  of  heat  reaches  us 
from  these  suns.  Consequently  all  the  heat  of  the  stars 
is  ignored  so  far  as  our  system  is  concerned.  Again, 
gravitation  is  as  universal  as  light  and  heat;  is  as  really 
a  form  of  working  energy  as  the  former;  is  expended 
and  renewed  as  incessantly ;  must  have  a  source  and  a 
destination,  as  much  as  light,  heat  or  any  other  form  of 
energy;  in  other  words,  must  form  a  link  in  an  end- 
less chain  or  an  arc  of  a  circle.  In  fact,  it  is  not 
expressing  the  truth  too  broadly  to  say  that  energy 
never  stands  still.  Yet  so  far  as  I  know,  no  writer  has 
seriously  undertaken  to  bring  this  great  force  in  nature 
into  correlation  with  other  forms  of  energy. 


292  SUN  SPOTS. 

The  main   propositions    herein    advanced   and    de- 
fended are  three : 

1.  That  the  universal  ether  is  still  the  abode,  though 
in  diversified  forms,  of  the  whole  sum  total  of  all  the 
energy  with  which  it  was  replete  in  the  nebular  state, 
when  the  heavens  were  aglow  and  "the  elements  dis- 
solved   with    fervent    heat."     This    energy   in    varied 
forms,  however  insensible,  is  to  the  last  iota  still  extant, 
or  else  conservation  has  failed  to  conserve.     It  leaves 
the  suns  as  heat,  but  during  long  progresses  through 
space  turns  to  mechanical   force  and   other  forms  of 
energy,  only  to  reappear  as  heat  in  the  solar  orbs  ad 
eternum\   perhaps   by  electrical   vibrations  of   atomic 
diamond  dust  in  the  photosphere ;  perhaps  simply  by 
arrested  mechanical  motion ;  perhaps  by  a  change  in 
vibration  analogous  to  the  sympathetic  motion  which 
one  vibrating  body  awakens  in  another.     In  fact,  every 
metamorphosis  of  energy  is  the  arrest  of  one  kind  of 
motion  and  the  inauguration  of  another. 

2.  That  this  same  energy  in  the  form  of  mechanical 
motion  pervades  all  space,  moving  in  right  lines  and 
attacking  every  molecule  and  every  mass  equally  on 
every  side,  except  where  intercepted  by  one  molecule 
or   mass   from    others.     The    nearer    the    intercepting 
bodies  are  to  each  other,  the  more  rays  of  force  they 
will  intercept  from  each  other  in  the  proportion  of  the 
inverse  squares  of  the  distances,  thus  marking  lines  of 
least  resistance  in  which  all  the  bodies  will  infallibly 
seek  to  approach  each  other.     All  wTill  recognize  this  as 
gravitation. 

3.  The  planets,  satellites  and  planetoids,  revolving 
around  the  sun  writhin  or  near  the  belt  of  the  Zodiac, 
must  and  do  intercept  from  the  sun's  equatorial  regions 


CONCLUSION.  293 

a  portion  of  the  emanations  of  a  wide  belt  of  the 
heavens.  All  will  admit  that  these  emanations,  how- 
ever feeble,  or  however  puissant,  are  in  the  form  of 
motion  or  energy  convertible  into  heat.  These  inter- 
ceptions or  shadows  must  lower,  however  slightly,  the 
temperature  of  the  equatorial  regions  of  the  sun,  and 
hence  condensation  and  precipitation  of  portions  of  the 
photospheric  clouds,  exhibiting  the  phenomena  of  sun 
spots. 

This  trinity,  inexpressibly  grand,  infinitely  compre- 
hensive, comprises  a  cycle  so  vast  as  to  include  the 
light  and  heat  of  every  sun  and  every  known  form  of 
energy. 

FINIS. 


APPENDIX. 

SIR  ISAAC  NEWTON  AND  DR.  FARADAY. 

NEWTON. 

IF  the  writer  can  show  that  the  theory  of  gravitation  by 
means  of  undulations  and  interceptions  is  countenanced 
directly  or  by  necessary  deduction,  by  two  such  imperial 
names  in  science  as  Newton  and  Faraday,  it  will  go  far 
toward  convincing  the  intelligent  reader  of  its  truth, 
though  truth  does  not  always  depend  on  the  authority  of 
great  names. 

I  will  here  quote  all  that  part  of  Newton's  third  letter 
to  Bentley,  which  relates  to  gravitation,  and  also  the  21st 
Query  from  his  treatise  upon  Optics: 

"  It  is  inconceivable  that  inanimate  brute  matter  should,  without 
the  mediation  of  something  else  which  is  not  material,  operate  upon 
and  affect  other  matter,  without  mutual  contact,  as  it  must  do,  if 
gravitation,  in  the  sense  of  Epicurus,  be  essential  and  inherent  in  it. 
And  this  is  the  reason  why  I  desired  you  would  not  ascribe  innate 
gravity  to  me.  That  gravity  should  be  innate,  inherent,  and  essen- 
tial to  matter,  so  that  one  body  may  act  upon  another  at  a  distance, 
through  a  vacuum,  without  the  mediation  of  anything  else  by  and 
through  which  their  action  may  be  conveyed  from  one  to  another,  is 
to  me  so  great  an  absurdity  that  I  believe  no  man,  who  has  in  philo- 
sophical matters  a  competent  faculty  of  thinking,  can  ever  fall  into 
it.  Gravity  must  be  caused  by  an  agent  acting  constantly  according 
to  certain  laws,  but  whether  this  agent  be  material  or  immaterial,  I 
have  left  to  the  consideration  of  my  readers." 

21st  Query.  "  Is  not  this  medium  [ether]  much  rarer  within  the 
dense  bodies  of  the  sun,  stars,  planets,  and  comets,  than  in  the 
empty  celestial  spaces  between  them?  And,  in  passing  from  them 
to  great  distances,  doth  it  not  grow  denser  and  denser  perpetually, 


APPENDIX. 

and  thereby  cause  the  gravity  of  those  great  bodies  toward  one 
another,  and  of  their  parts  toward  the  bodies;  every  body  endeavor- 
ing to  go  from  the  denser  parts  of  the  medium  toward  the  rarer?" 

Many  things  have  been  rendered  clear  by  modern  sci- 
ence that  were  crude  in  Newton's  time.  His  conception 
of  ether  is  now  quite  inadmissable.  But  six  things  are 
evident  from  these  quotations  and  Newton's  definition  of 
gravitation.  He  held,  1st,  that  gravitation  is  not  and 
cannot  be  inherent  and  self-originated  in  the  particles  or 
aggregations  of  matter;  3d,  that  it  must  consequently 
originate  outside  of  the  bodies  affected  by  it;  3d.  that  it 
operates  from  great  distances  outward  in  space,  that  is, 
from  the  region  of  the  fixed  stars,  or  at  least  from 
that  direction,  and  directed  inward  toward  the  sun;  4th, 
that  it  acts  through  some  agent  or  medium,  either  material 
or  immaterial,  by  which  he  undoubtedly  meant  either  ordi- 
nary or  ethereal  matter.  As  we  know  there  is  no  ordinary 
matter  impinging  against  the  earth  and  pushing  it  toward 
the  sun,  the  medium  must  be  an  ethereal  one;  5th,  we 
know  from  his  definition  that  he  held  gravity  to  be  a  force 
varying  directly  as  the  masses,  and  6th,  inversely  as  the 
squares  of  the  distances. 

Newton  perceived  clearly  that  gravity  could  only  act 
through  a  medium  connecting  the  source  and  the  object 
of  this  force.  In  his  queries  he  expressly  names  the  ether 
as  this  medium.  Had  he  added  that  this  medium  acted  by 
undulations  of  mechanical  force  and  their  mutual  inter- 
ceptions by  the  bodies  between  which  the  force  is  exerted, 
and  also  that  the  force  is  unfailing  by  reason  of  its  opera- 
tion in  the  grand  circuits  of  the  unceasing  transmissions 
and  transmutations  of  Nature's  energies,  which  can  no 
more  stop  than  the  machinery  of  Nature  herself,  then  his 
completed  conception  of  gravity  would  have  been  identi- 
cal with  the  one  here  presented. 

I  submit  the  question,  Is  there,  without  these  additions 


APPENDIX.  297 

any  way  in  which  he  could  have  completed  his  concep- 
tion, or  is  there  any  other  theory  possible  which  will  har- 
monize all  the  six  Newtonian  attributes  of  gravity  above 
named  ? 

FARADAY. 

Dr.  Faraday  has  demonstrated  that  the  popular  concep- 
tion of  gravity  is  inconsistent  with  the  now  generally 
accepted  doctine  of  conservation  of  energy.  I  quote  from 
"  The  Correlation  and  Conservation  of  Forces,"  Youman's 
collection,  page  363: 

"I  believe  I  represent  the  received  idea  of  the  gravitating  force 
aright  in  saying  that  it  is  a  simple  attractive  force  exerted  between 
any  two  or  all  the  particles  or  masses  of  matter,  at  every  sensible  dis- 
tance, but  with  a  strength  varying  inversely  as  the  square  of  the  dis- 
tance. The  usual  idea  of  the  force  implies  direct  action  at  a  distance, 
and  such  a  view  appears  to  present  little  difficulty,  except  to  New- 
ton, and  a  few,  including  myself,  who  in  that  respect  may  be  of  like 
mind  with  him. 

"  This  idea  of  gravity  appears  to  me  to  ignore  entirely  the  princi- 
ple of  the  conservation  of  force;  and  by  the  terms  of  its  defini- 
tion, if  taken  in  an  absolute  sense,  '  varying  inversely  as  the  square 
of  the  distance,'  to  be  in  direct  opposition  to  it,  and  it  becomes  my 
duty  now  to  point  out  where  this  contradiction  occurs,  and  to  use  it 
in  illustration  of  the  principle  of  conservation.  Assume  two  parti- 
cles of  matter,  A  and  B,  in  free  space,  and  a  force  in  each,  or  in 
both,  by  which  they  gravitate  toward  each  other,  the  force  being 
unalterable  for  an  unchanging  distance,  but  varying  inversely  as  the 
square  of  the  distance,  when  the  latter  varies.  Then  at  the  distance 
of  ten,  the  force  may  be  estimated  as  one,  whilst  at  the  distance  of 
one,  that  is,  one-tenth  of  the  former,  the  force  will  be  one  hun- 
dred; and  if  we  suppose  an  elastic  spring  to  be  introduced  between 
the  two  as  the  measure  of  the  attractive  force,  the  power  compress- 
ing it  will  be  a  hundred  times  as  much  in  the  latter  case  as  in  the 
former.  But  from  whence  can  this  enormous  increase  of  power 
come?  If  we  say  that  it  is  the  character  of  this  force,  and  content 
ourselves  with  that  as  a  sufficient  answer,  then  it  appears  to  me  we 
admit  a  creation  of  power  and  that  to  an  enormous  amount;  and 
yet,  by  a  change  of  condition  so  small  and  simple  as  to  fail  in  leading 


298  APPENDIX. 

the  least  instructed  mind  to  think  that  it  can  be  a  sufficient  cause, 
we  should  admit  a  result  which  would  equal  the  highest  act  our 
minds  can  appreciate  of  the  working  of  infinite  power  upon  matter; 
we  should  let  loose  [disregard]  the  highest  law  in  physical  science 
which  our  faculties  permit  us  to  perceive,  namely,  the  conservation 
of  force.  Suppose  two  particles,  A  and  B,  removed  back  to  the 
greater  distance  of  ten,  and  then  the  force  of  attraction  would  be 
only  a  hundredth  part  of  that  they  previously  possessed ;  this,  ac- 
cording to  the  statement  that  the  force  varies  inversely  as  the  square 
of  the  distance,  would  double  the  strangeness  of  the  above  results ; 
it  would  be  an  annihilation  of  force  —  an  effect  equal  in  its  infinity 
and  its  consequences  with  creation  and  only  within  the  power  of 
Him  who  has  created." 

Again  I  quote  from  page  367: 

"The  principle  of  the  conservation  of  force  would  lead  us  to 
assume  that  when  A  and  B  attract  each  other  less,  because  of  increas- 
ing distance,  then  some  other  exertion  of  power,  either  within  or 
without  them,  is  proportionately  growing  up;  and  again,  when 
their  distance  is  diminished,  as  from  ten  to  one,  the  power  of  attrac- 
tion, now  increased  a  hundred  fold,  has  been  produced  out  of  some 
other  form  of  power  which  has  been  equivalently  reduced." 

Again  from  page  368: 

"For  my  own  part  many  considerations  urge  my  mind  toward 
the  idea  of  a  cause  of  gravity  which  is  not  resident  in  the  particles  of 
matter  merely.  *  *  *  1  have  already  put  forth  considerations 
regarding  gravity  which  partake  of  this  idea,  and  it  seems  to  have 
been  unhesitatingly  accepted  by  Newton." 

I  refrain  from  quoting  more  to  the  same  effect.  Enough, 
I  think,  has  been  quoted  from  this  close  reasoner  to  show 
that  the  theory  of  gravity,  erroneously  attributed  to  New- 
ton, 1st,  involves  the  denial  of  the  doctrine  of  conserva- 
tion, and  2d,  replaces  it  by  a  theory  which  endows  inert 
matter  with  the  power  of  the  alternate  creation  and  anni- 
hilation of  force. 

On  the  contrary,  the  theory  of  gravity  by  propagations 
and  interceptions  of  waves  of  mechanical  force,  1st,  con- 
serves conservation,  and  2d,  accounts  for  the  alternate 


APPENDIX.  299 

increase  and  decrease  of  this  force,  not  by  creation  and 
annihilation,  but  by  an  equilibration  of  positive  and 
negative  forces  by  the  propagation  and  interceptions,  not 
of  hypothetical,  but  of  actual  waves  of  mechanical  force 
with  which  the  heavens  are  replete.  See  ante  pages  110 
and  111. 

This  theory  discloses  a  force  growing  up  on  occasion  to 
infinity,  because  it  proceeds  from  an  infinite  source, 
namely,  all  the  emanations  of  force  from  all  the  denizens 
of  space,  limited  only  on  one  hand  by  the  mass  to  be 
moved,  and  on  the  other  by  the  amount  of  the  force  inter- 
cepted. Its  diminution  down  to  an  infinitesimal  is  also 
accounted  for  on  the  well  known  principles  applicable  to 
all  radiant  forces.  The  negation  of  force  diverges  and 
diminishes,  or  rather  the  positive  force  increases,  out- 
wardly from  the  intercepting  mass  according  to  the  laws 
of  all  radial  action,  to  wit:  the  law  of  the  inverse  squares. 

In  the  case  of  Dr.  Faraday,  also,  I  submit  the  question, 
Is  there  any  other  conception  of  gravity  that  can  remove 
the  otherwise  insuperable  objections  urged  by  him,  and 
bring  this  great  force  into  harmony  and  correlation  with  all 
the  other  forces  in  Nature  ? 


INDEX. 


Action  at  a  distance,  131-137. 

Aggregations  of  matter;  how  held 
together,  14. 

Almighty  atoms,  156. 

Appearance  of  sun  spots,  265-277. 

Appendix,  29.V-299. 

Arago  on  gravitation,  157. 

Aristotle,  219. 

Astronomical  argument  for  the- 
ory of  gravitation,  123,  157. 

Astronomical  objections  to  agen- 
cy of  the  ether  in  gravitation 
answered,  157. 

Atmospheric  condensation  theory 
of  solar  heat,  18. 


Bentley,  Newton's  letter  to,  122, 

295. 
Boiling  appearance  in  sun  spots, 

269. 
Bond  between  sun  and  earth,  167. 


Cannon  ball  contracting  by  cool- 
ing, 11. 

Capacity  for  heat ;  how  increased 
and  diminished,  14. 

Carbon  in  photosphere,  256-264. 

Carrington,  observations  by,  236 ; 

Cavendish  experiment,  illustrat- 
ing gravitation,  171-175. 

Challis,  Prof.,  on  action  at  a  dis- 
tance, 134. 

Classification  of  theories  of  solar 
heat,  34. 

Combustion  in  the  sun  impossi- 
ble, 5. 

Conclusion,  290-293. 

Condensation  theory  of  solar  heat, 
10. 


Conflagration  theory  of  solar  heat, 

Conservation  of  energy,  3,  90-92. 

Convection  currents,  30. 

Cooling  of  the  sun  hvpothetical 
only,  39. 

Cooling  process  not  an  endless 
one,  61,  75. 

Copernicus,  106,  163. 

Croll,  James,  on  action  at  a  dis- 
tance, 134. 

Crookes,  W.,  on  mechanical  re- 
pulsive force,  110. 

Currents  in  photospheric  clouds 
analogous  to  terrestrial  cloud- 
bearing  winds,  but  in  reversed 
directions,  234-238. 

Cyclonic  spots,  237-239. 


Daniels,    Prof.   A.,   on  ethereal 

waves,  111. 

Diffusion  of  light  and  heat,  38. 
Dissipation  of  energy,  93-98. 
Distribution  of  sun  spots  in  belts 

north  and  south  of  the  equator, 

240-247. 

Dream,  not  all  a  dream,  210. 
Du  Bois  Raymond  on  action  at  a 

distance,  135. 
Duration  of  the   universe  in  the 

past,  2. 


Earth  as  a  point  for  observation, 
41 ;  once  a  part  of  the  sun, 
59;  why  cooled,  and  not  the 
sun,  59-63;  sufficiently  heat- 
ed, would  become  a  little  sun, 
228. 

Energy,  what?  80.  81,  90;  new 
forms  improbable,  75;  exist- 


302 


INDEX. 


ing  forms  not  likely  to  be  aug- 
mented at  expense  of  heat.  75; 
potential,  81 ;  identical  with 
matter  in  motion,  189. 

Equalization  of  light  and  heat, 
38. 

Equations;  every  exhibition  of 
force  equal  to  one  that  precedes 
and  one  that  follows,  55. 

Ether;  what?  196-205;  com- 
pared to  an  ocean,  44;  not  a 
reservoir,  53;  sun  communi- 
cates with  other  bodies  only 
through  the  ether,  56;  ether 
an  equilibrator,  38  ;  acts  by  vi- 
brations only,  208;  enormous 
intensity  of  energy  attainable 
by,  201. 

Ethereal  undulations  proceed 
from  non-ethereal  senders  to 
non-ethereal  receivers,  53. 

Ethereal  vibrations  metamor- 
phosed at  the  sun  perhaps  by 
electrical  action,  65  ;  of  me- 
chanical force,  110;  nature  of. 
206-210. 

Experiment,  Cavendish,  171. 

Experiments  by  Drs.  Konig  and 
Richarz,  applied  to  gravita- 
tion, 176-181. 

Extension  of  universe  in  space,  3. 


Fabricius,  219. 

Faeul®,  270,  272. 

Faraday,  Dr.,  on  gravitation,  155, 
156,  297,  298. 

Fixed  stars  communicate  no  ap- 
preciable heat  to  earth,  41 ;  the 
source  of  gravitation,  107,  145, 
146. 


Galileo,  219. 

Granules  in  photosphere,  273; 
emit  four-fifths  of  light  and 
heat  of  the  sun.  277. 

Gravitation,  99-105;  law  of,  owed 
to  Newton,  99;  cause,  100;  mo- 
dim  operand  i,  101 ;  by  propul- 
sion and  interception,  101,  115; 


definitions,  103;  by  pushes,  and 
not  pulls.  104;  illustrations. 
106-108,  119.  120,  144;  not  a 
positive  force  exerted  by  the 
sun,  114:  operates  between 
bodies  widely  separated,  117: 
must  act  through  a  medium. 
117;  according  to  Newton,  arts 
through  the  ether  as  the  me- 
dium, 295,  296:  (lorribed  by 
Newton,  122;  astronomical  ar- 
gument, 123,  157:  relation  to 
correlation  and  conservation 
of  energy,  126-130  :  compared 
with  light  and  heat.  138-143; 
summary  in  regard  to,  135-137; 
concluding  remarks  on,  213- 
218. 

H 

Heat,  quantity  radiated  by  the 
sun,  31-33;'  cannot  travel  be- 
yond bounds  of  the  universe, 
37;  indestructible,  39,  40;  from 
all  the  suns  must  change  to 
other  forms  of  energy,  42 ;  the 
primal  and  unspecialized  form 
of  all  energy,  43,  47,  77;  con- 
stantly changing  to  other  forms 
of  energy.  50;  now  radiating 
from  sun  not  simply  the  residue 
of  his  original  endowment,  52 : 
outflow  of,  cannot  be  perpetual 
without  a  corresponding  influx. 
54;  necessarily  changed  to  other 
forms,  57. 

I 

If—,  287. 

Illustrations  of  gravitation,  106- 
108,  119,  120,  144. 


Jupiter,  shadows  cast  by,  232; 
from  immense  mass,  etc.,  must 
dominate  in  the  matter  of  sun- 
spots,  248:  sometimes  assisted, 
and  at  others  antagonized,  by 
other  planets  as  to  times,  248. 


INDEX. 


303 


K 

Konig.  Dr.  A.  and  Richarz,  ex- 
periments by,  176. 


Langley,  S.  P.,  determinations  of 
relative  heat  of  photosphere, 
penumbra,  and  umbra  of  the 
sun,  225;  illustrations  by,  208, 
276  ;  on  granules  and  pores, 
277;  on  amount  of  heat  radi- 
ated by  the  sun,  33;  on  light 
and  heat  emitted  by  granules 
and  pores,  277. 

Le  Sage's  ultramundane  corpus- 
cles, 152-154. 


M 


Mallets,  round-headed,  without 
handles,  144. 

Maxwell,  J.  Clerk,  on  pressure 
and  tension,  167-170. 

Mayer,  Dr.  J.  R.,  on  amount  of 
heat  radiated  by  the  sun,  31. 

Metamorphosis  of  motion  and  en- 
ergy, 185-195. 

Meteoric  theory  of  solar  heat,  5. 

Millpond  compared  with  the  sun, 
51. 

Mohr,  F.,  on  action  at  a  distance, 
135. 


N 


Nature  a  munificent  parent,  60. 

Nebula?  composed  of  incandescent 
gases,  69. 

Nebular  hypothesis,  68;  heat,  how 
disposed,  of,  70-79  ;  condition 
caused  by  heat,  78. 

Newcomb,  Prof.  S.,  on  cooling  of 
sun,  52,  226. 

Newton,  Sir  Isaac,  on  ether,  206; 
Newton's  third  letter  to  Bent- 
ley,  122,  295 ;  his  conception  of 
gravitation,  296. 

Newtonian  attributes  of  gravita- 
tion, 296. 


Objections  to  agency  of  ether  in 
gravitation  answered,  158-161. 
Ontology,  162. 


Penumbra?,  220,  223,  236. 

Perihelia  of  Jupiter  compared 
with  other  planets,  248;  as  re- 
lated to  sun-spot  maxima,  249- 
255. 

Periodicity  of  sun-spot  maxima, 
248-255. 

Perpetuation  of  solar  heat,  63. 

Photosphere,  brightest  and  hot- 
test part  of  sun,  224,  229 ;  prob- 
ably composed  of  incandescent 
carbon  particles,  256-264;  ra- 
diates all  the  heat  given  out  by 
the  sun,  and  must  be  the  part 
cooled  most  rapidly,  229;  being 
the  hottest  part  of  the  sun,  it 
must  receive  its  heat  from  with- 
out, and  not  from  within,  229. 

Pores,  273;  form  four-fifths  of 
the  solar  surface,  and  emit  only 
one-fourth  of  his  light  and  heat, 
277. 

Postulates,  2. 

Potential  energy,  17,  80-89. 

Pressure,  all  force  exerted  by 
pressure  or  tension,  168-170. 

Preston,  S.  T.,  on  heat  by  falling 
meteors,  9;  on  ether,  201,  202; 
on  potential  energy,  89. 

Proctor,  R.  A.,  on  solar  heat  by 
contraction,  13 ;  on  Dr.  Sie- 
mens' theory  of  solar  heat,  29. 


Queries  by  Newton,  206,  295. 


Recapitulation  in  regard  to  sun 
spots,  278,  283. 

Reductiones  ad  absurda,  182-184. 

Richarz,  Dr.  F.,  and  K5nig,  ex- 
periments by,  176. 


304 


INDEX. 


Scheiner,  219. 

Secchi,  Father,  on  action  at  a  dis- 
tance, 135. 

Semi-delusions,  146-149. 

Siemens',  Dr.  C.  W..  theory  of 
solar  heat,  24,  26,  27. 

Solar  heat  by  falling  meteors,  5 ; 
by  contraction  of  the  sun,  10 ; 
imports  and  exports  equal,  16; 
by  potential  energy,  17;  by  at- 
mospheric condensation,  18;  by 
combustion  of  gases  in  photo- 
sphere, 26 ;  a  new  theory  of,  36 : 
by  ethereal  vibrations,  48 ;  per- 
petuation of,  63. 

Spectra,  of  three  kinds,  69. 

Spectroscope,  68. 

Stall o,  J.  B.,  quotations  from, 
134,  135;  on  potential  energy, 
82. 

Startling  thought,  78. 

Stewart  and  Tait  on  potential  en- 
ergy, 17  ;  on  action  at  a  dis- 
tance, 135. 

Stewart,  Balfour,  on  dissipation 
of  energy,  93. 

Stress  and  strain,  167. 

Sun  a  consumer  as  well  as  a  pro- 
ducer—  a  receiver  as  well  as  a 
sender,  48  ;  receives  his  heat 
from  other  suns,  56. 

Sun  spots,  dependent  on  solar 
weather,  231  ;  caused  by  the 
shadows  of  Jupiter  and  other 
planets,  232 ;  these  shadows  the 
complement  of  gravitation,  232; 
unequal  rotation  of,  234:  cause 
of  unequal  rotation,  235  •.  seek 
to  locate  themselves  perpendic- 


ularly under  the  nearer  planets. 
249  ;"  eruptive  theory  of,  270; 
immense  size  of,  266. 
Sun-spot  maxima  on  an  average 
correspond  nearly,  if  not  ex- 
actly, with  the  Jovian  periods, 
250*;  compared  in  table,  250; 
proposed  laws,  253. 


Tait,  P.  G.,  on  solar  heat,  17;  on 
action  at  a  distance,  135. 

Tension,  167,  168,  173,  175. 

Thomson,  Sir  William,  on  con- 
vection currents,  30. 

Transformation  of  energy,  185. 

U 

Ultramundane  corpuscles  of   Le 

Sage,  152-154. 

Universal  atmosphere,  19,  24. 
Undulations  of  ether,  145. 

W 

Weight,  149-151. 

Williams,  W.  Matthieu,  theory 
of  solar  heat,  18;  on  waves  of 
force,  110. 

Winchell,  Prof.  Alex.,  on  evolu- 
tion of  nebular  matter,  74. 

Wolf,  on  sun-spot  maxima  and 
minima,  248,  250. 


Y"oung,  Prof.  C.  A.,  on  solar  heat 
by  shrinkage,  1 1 ;  on  amount  of 
heat  radiated  by  the  sun,  23; 
extract  and  illustration,  222. 


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